Argonians are famous for being guerilla warriors, shamans and swimmers, so i assume that atleast one of the 2 monster sets will be inspired by that while the other one could be influenced by the enemy which we have to face off.

Stealth monster set variant:
1 set: stam regen and max stam
2 set: A second attack/ability can be fired from stealth and benefits from stealth bonus before being revealed

Healer shaman set variant:
1 set: increased healing done
2 set: Increases max health from a healed target by x for 10 seconds

Alchemy shaman set variant:
1 set: max health, magicka, stam with 50% reduces value
2 set: Increases potion strength/duration by 50%, allows to equip a second poison

Hist shaman set variant:
1 set: max health
2 set: blocking an attack restores x% of your max health

Just some ideas, what do you guys think how the next monster sets turn out?