[AreaOfEffect]

From my limited experience with Ctis I can tell you two things. Placement and Magic.

All of C'tis' units are situational and specialized. Some factions can at often times just buy one unit and apply critical mass to acheive victory without fail. Vanhiem/Midgard is the biggest culprit I know of for this kind of brute strategy. With C'tis you need to know the role of every unit and use them all in order to get maximum effect. Getting the corus of C'tis units to sing together is difficult. In the end it may just come down to luck though.

The best use of poisen slingers I've seen is in spreading them all around the field as just one unit and have them target archers. It only takes eight or nine of them in a large army to deal a lot of hurt this way.

The units however are a weak wall to throw up between the units that matter and the enemy. In my opinion it is the mage power of C'tis that wins wars. There is a reason why your best mages can be made everywhere you go. I can remember several instances where I lost battles solely due to skelly spam and magical artillary. Again, making C'tis sing is a matter of tediousness. Study the list of magic spells and know how to weild them. 90% of your victory depends on knowledge of magic.

Good luck.