I'm being sorely tempted to start an IG army just for the sentinels... though I would be more likely to run 5 then the full 9.
I recon that units of 3 with autocannons outflanking will be a solid fire support unit and fairly effective so long as they aren't facing a lot of medium-high powered long range anti-tank (eg SW long fangs with missile launchers). Against armies that rely on melta weaponry you can just outflank and then if you do enter play on the side closest to anti-tank units you can just enter on the far edge of the side... you'll be in range but well out of melta range.
I think 2 units would be about the max though... they would be doing the same role so multiple units would reduce each others' impacts, they would also force you to bunch up (especially if you get unlucky on the outflanking roles), making it worth sending an expensive but killy unit out to deal with you.

Personally the sentinel I want is the armoured sentinel with plasma cannon. You'd be able to smash enemy TEQ/MEQ while being AV12 to most incomming fire (making you almost as hard to kill as a dreadnought and almost as killy for only 2/3 the cost). The best part is that in combat you are an AV12 walker... so are a pretty effective tarpit. I intend to seed my IG army with 2-3 such sentinels if I ever do get round to collecting IG.... that way I have a gun line with mobile tarpits for 90% of the units out there that'll want to kill me in combat and they are cheap enough to still have an army to go with them.

 

Sentinels are good units, just not top shelf, plus get sidelined because IG have that other more efficient unit..what's it called again:biggrin: - Vendetta.

Personally I would only choose an Armoured one over a Scout if you want to be a bit better at tarpitting due to having higher AV, or if you want a Plasma Cannon. Other than that the Outflanking ability of the Scout makes it a more flexible unit gameplay-wise...Armoured one is more a static firebase - type unit, and IG can get that in spades from plenty of other choices in the Codex.

I wouldn't go tarpitting any enemy unit that has a PF, etc or even S5 weapons, because neither will be tieing that unit up for long anyway.

Squadron -wise 2 is enough, especially if you give them multiple shot weapons like the AC because it mitigates the BS3 somewhat.

If you play on terrain-heavy boards then they survive for longer, plus it would pay to have plenty of other more threatening vehicles on the board anyway simply to make the enemy have to choose what to target.

Still, if you're going for a 'themed' list then just do it...I have 10 Sentinels and like the look of the model - that's reason enough to field them., just not as devastating as other choices might be.

 

I experimented with plasma cannon Armored Sentinels heavily, and they simply aren't worth the points. Armored Sentinels tend to get used as a tarpit, and for good reason. For this reason, most of the time they end up not firing their plasma cannons anyways, so the extra points spent on the weapon upgrade are pretty well wasted.

 

One of the things I was contemplating was two themed lists that revolved around the use of scout sentinels.

One would be a fully mechanized list that is sort of geared towards fast attack where all my units would be in Chimeras. No use of heavy weapons except those mounted on the vehicles. I like the idea of a sentinel swarm that can also take advantage of cover. I'm just not certain of how flimsy they will be. Can they take damage or is it a "if the enemy looks at you the wrong way you are dead" scenario?

Another themed list would also have the same sentinel setup except it'd be a more infantry themed list. I was thinking a unit that was supposed to be more of a light infantry/recon taskforce that had the sentinels for scouts and heavy weapon support.

That's one of the reasons I bring this up. I sort of want to make them the centerpiece of each of these armies, but having no experience am not sure if it will all collapse in on itself cause the unit itself can't really perform.

 

One of the things I was contemplating was two themed lists that revolved around the use of scout sentinels.

One would be a fully mechanized list that is sort of geared towards fast attack where all my units would be in Chimeras. No use of heavy weapons except those mounted on the vehicles. I like the idea of a sentinel swarm that can also take advantage of cover. I'm just not certain of how flimsy they will be. Can they take damage or is it a "if the enemy looks at you the wrong way you are dead" scenario?

Scout sentinels have minimal armor and are Open-Topped so yeah, they die rather quickly, though if you can get them into cover then they can last a good while.

Another themed list would also have the same sentinel setup except it'd be a more infantry themed list. I was thinking a unit that was supposed to be more of a light infantry/recon taskforce that had the sentinels for scouts and heavy weapon support.

Would be a very cool idea for friendly games.

That's one of the reasons I bring this up. I sort of want to make them the centerpiece of each of these armies, but having no experience am not sure if it will all collapse in on itself cause the unit itself can't really perform.

I wouldn't recommend making Sentinels the focus of your army. While cool, they're intended to be support units, light recon and fire support. They're really not very good at engaging in direct firefights with the enemy army as they fold extremely easily if focused on by much of anything.

 

Even if you get them cover, AV10 open-topped just doesn't last long.

 

Cheap FotM outflanking Autocannons. It's what... 120pts? For 3 Autocannon sentinels. You'll usually see a light transport downed each turn, and they are reasonably resilient unless someone turns multiple anti-tank weapons on them. Some exceptions, such as Assault Cannons or other medium strength high RoF weapons can damage them, but not many people would want to dedicate 3-4 Lascannon shots to reduce their effect when Vendetta's, Valkyries, Manticores, and Chimera's are floating around.

But yes, Move and Fire Autocannon's are good choices if you have nothing better to put there. Or missile launchers - sacrificing Anti-vehicle capabilities for Anti-horde capabilities.

Of course, you have to remember that they can only move 6" and target one vehicle with 6 BS3 S7 Shots, whereas a Vendetta for a little more can move 6", target one vehicle with 3 Twin Linked BS3 S9 AP2 Shots, as well as taking Heavy Bolter Sponsons to put out 6 BS3 S5 AP4 shots, with the capability to take troops, and move fast with them for 20pts more, and I'd happily sacrifice 20pts elsewhere to take another Vedetta.

 

Lets do the math, shall we? 3 autocannons is 3 autocannon hits at BS3, let's say we're firing against AV11, so that's, on average 1 pen and 1/2 a glance. The math says that it's about 1/3 of a light transport downed every round.

Compare that to a vendetta, at only 10 points more, and you're looking at 2.25 lascannon hits, which is A bit more than 1 1/3 pen, and a bit more than 1/3 of a glance. So you're looking at about a 30% increase in average damage each turn, for about an 8% increase in cost.

I'll grant you that the sentinels are a bit more durable to the odd single-lascannon shot, but I'd say they'd both die fairly easily under fire from the more common unit such as missile launcher long fangs.

 

I wouldn't really bother Outflanking - purely on the basis that it wastes 1-4 Shooting Phases from the unit, and they aren't improved by being closer to the enemy, only arc changes...in which case, why bother? Rhinos and Razorbacks (and Venoms/Raiders) have the same Front as Side, so...no benefit.

 

Yeah, sorta wrote as I was thinking it. It's not that Sentinels are poor, but that there are better options.