I should note that I play on Xbox, so I can only map one power per squadmate. If I want to play without pausing (or with minimal pausing), that means I can only really use one power per squadmate, so that changes how I spec my squadmates usually.
Hehe, I'm on PC and I pause all the time, but that's a bitt offtopic I suppose.
James:
For James, I usually ignore Carnage since the cooldown is oppressive and I do not really use him a whole lot anyway. I usually spec James for survivability, grenades, and Incendiary Ammo:
Fortification: Durability - Shield Recharge - Durability
Incendiary Ammo: Squad Bonus - Headshots - Explosive Burst
Carnage: -
Frag Grenades: Damage - Grenade Count - Shield Damage
Passive: Health and shields - Shield Recharge - Fortification
Notes:
- Incendiary Ammo, I go Squad unless I have my own Incendiary Ammo (Soldier or Vanguard), in which case I give him the damage bonus. If I am using Squad Cryo Ammo or Squad Disruptor, then I ignore his Incendiary Ammo
- If you want more damage out of his ammo, then go power damage at rank 5 of Fortification and passive.
Well this probably has to do with the pausing thing, but I do max out carnage, and leave fortification completely empty (I do think you have to reset his powers to get 0 points in fortification). The reason to put no points in it is that I actively direct my squad to attack enemies, and this will sometimes cause him to active the skill. That, and James is already a near indestructable tank without the skill.
The huge cooldown for carnage doesn't really matter in my opinion, because he also has the grenades which can be used while on cd.
So my James looks like this:
Fortification - not a single point
Carnage - Damage, recharge speed, armoured damage.
Incendiary Ammo - squad/damage, headshot, explosive burst
Frag Grenade - damage, bleed Damage, shield overload (you find grenades EVERYWHERE, no need to go for extra capacity)
Arms Master - weapon damage, power damage, squad bonus (+20% shields on the entire squad is quite f'ing something if you ask me!)
And I give the guy a particule rifle. Works very well with his ammo power.
Don't have much to say about Kaidan, he usually dies.
OP: if you're on a playthrough with a dead Tali, I'd advise you to take Javik instead of Kaidan. They have some interesting comments on Rannoch.