Join Date: Jan 2009
Location: Worcestershire, UK
If you are going to take a savage orc in the unit make it a unit of savages: if you are going to have the downside of frenzy anyway you might as well have the extra attacks).
I would probably view 30 as the minimum unit size... although personally I rarely go below 35. 20 is a bit small for a combat unit of any type unless you know you'll hit hard and hit first (such as high elves), but with low initiative units (or with great weapons) its worth taking much bigger units.
As for the goblin great shaman... its really up to you. Characters on monsters are not a particularly strong combination as cannons (or other template based artillery/magic) hit both, meaning one or 2 cannon hits and both the character and monster are normally dead (often the character won't survive 1 hit without the lookout sir he would get in a unit). Secondly mages on monsters are even worse off since you can't put the monster into combat without everyone in base contact being able to attack the mage (who is unlikely to have better then 6+ armour with 4++ ward maximum).
I think a spidershrine with a couple of cheap lv1s running alongside for extra channelling could be a very fun idea but I think it might button-hole you into using the spider as a support unit to buff magic rather then a the combat monster it really is.
I think it would be much more effective to have the spider on its own with a lv4 great shaman hidden away in a unit of infantry somewhere. Personally I would go for a night goblin lv4 so long as you have a backup mage or 2 to take over if his mushrooms prove to be too much for him (my personal combo of choice is lv4 night goblin with lv3 orc and possibly 1-2 lv1 night goblins with sneaky stabbin' attached to combat blocks)