I like that idea, but I have never played Straken before. I was pretty new to IG before they became AM. Maybe Straken('s Fist, JUST PUT THAT TOGETHER
Yes, I am the land shark that ate Straken's Fist...;-)
Why is he a good HQ choice? I have been using a PG equipped CCS mounted in a Chimera with 2/3 MG'd up Veteran squads with Exterminator support as the mobile aspect of my army, but after playing the solo 20 man blob I think I want to rack that up a bit. I like your whole Troops selection part, though it's a very different style of play than what I have been fielding.
Starting to think Veteran squads may be a thing of my past in games up to 2k. You can take so many varieties of 'shit you need in an army' from Platoons it's ridiculous. Stack that with relatively cheap and abundant Prescience and who gives a damn if they have BS3 instead of BS4. There's 2-3 times the number of them!
Well, I first started playing Straken because of his amusing and bad ass backstory, but also because I liked the idea of blob guard and wanted to play something a bit different to the veteran/mech spam everyone and his dog seemed to play in 5th edition. Straken back in 5th was excellent for blobs because Furious Charge gave you +1 initiative as well as +1 strength (as I am sure you are aware with your Death Company how devastating it was), but also Counter-Attack. So, I always had a big deathstar unit with a 40-man blob with Straken nearby, i'd just camp on an objective and shot things to pieces from a distance, and if anyone tried charging that blob they would get tarpitted (counter-attack really helping with this) or wouldn't be able to chew through the entire blob.
The beauty of it was that the rest of my troops choices were mechanised (couple of vets and PCS in chimeras) and many players were often so psyched out and obsessed with trying to remove my blob that the faster mech-infantry went unnoticed: I also had a lot of artillery to back it up, and the odd leman russ. The whole thing was a Hammer and Anvil strategy that was fun to play because it used a bit of everything, the blob was really just bait but yet no one can really afford to ignore it as it's also full of firepower.
Well, I still try to play it like that: Sure, there is no longer that precious +1 Initiative to furious charge, but Straken is still a good choice if you are running even just 1 blob: Counter-Attack coupled with flamer overwatch makes it even more foolish for anyone to charge you, which forces opponents to stand and shoot, which is usually want you want, because not many armies can go toe to toe in a shooting match with guard.
Also, Straken is still exceptionally good in close combat for his price tag: Many people don't expect that from IG, which you can use to your advantage: Yep, Straken has AP2 attacks at I3. He also now has Monster Hunter, which is a nice bonus against Monstrous Creatures. He also has Armour bane, so can run upto tanks and smash them to death with his bionic fist...
He does very well against Terminators, especially when you are re-rolling hits in close combat with Prescience or a Priest for Hatred: Even against a Thundernator Sergeant in a challenge, the odds are in his favour, as scoring 3 wounds will land him a pretty good chance of killing the sergeant before he can retaliate.
Of course he does have weaknesses: Massed power weapon attacks from marines will cause him problems because of his poor invulnerable save and the fact they will be striking first. So you have to think a bit before charging in.
So yeah, Straken can hold his own in close combat, he can take out tanks, he can dish out orders, and he gives a really useful counter-attack/furious charge bubble to all units within 6" (put him between two blobs or behind one large one and you are golden). He also has tonnes of character. Just nice all round in my opinion. But you really have to build a large part of your list and strategy around him, I think.
The beauty of Guard is that they are very flexible: You can blobs, you can do veterans, you can do air Calvary (well, not so much anymore perhaps), you can do mech platoons, you can now also spam the hell out of Leman Russ'...Or mix and match to your liking.