I use Gorgotha, Khorvash, Amira and Wulfgarok(or Manticore if you don’t have Wulfy). An impervious troop in last slot prevents Kraken from devouring. Gorgotha tanks, generates mana for all and self-cleanses. Khorvash fills off Blue and provides damage, mana-drain and is a good secondary-tank. Wulfgarok boosts Amira’s true-damage by 5 (10 against Blue troops) and will occasionally be useful for a 2-for-1 kill. If you don’t have Wulfy, Manticore provides a targeted mana drain which will usually fill off a single green match. Neither Amira (unless stunned) nor Wulfy/manticore can be damaged by Mana Drain. Amira, especially if boosted by Wulfgarok, will generally one-shot kill any blue troop. Against very strong opponents, I may need to choose the order of targeting. That is, I may need to kill Mab (who usually has the highest life) last, which i want to do anyway since she can’t hurt my last two troops.
I use this team only against teams that are build around Blue troops (Justice League, Mab/Khorvash teams, etc.) Against a good team getting good luck, I may lose a troop or two (usually only when a Khorvash can cast 3 or more times), but it is extremely rare to lose when you use this team against its intended target.
If this one doesn’t suit you, my wife uses Khorvash, Spirit Fox, Amira, Wulfy/manticore, which is a little slower to collect mana, but also starts with 1.5 filled mana-drain troops.
I get what you’re saying here, but that isn’t my style. My lifetime invade win rate is over 95%, and tends to drop when I try to use a one-size-fits-all approach.