Yes whether or not the slann can be actually hit in the 2nd rank will be interesting, I kind of doubt it. If so it might want to take some kind of magical protection like the ethereal or regen. Not a big deal either way.
The slann doesn't actually strike, its the skink on his chair the pokes the enemy, so I wouldn't bother trying to tool it up for CC.
I am looking forward to running a slann and skink mage as my magic, assuming some better spells in the lore of heavens this should give some variety.
I wouldn't really want to run 2 slanns, but I can see it being very powerful, getting the best spells from 2 lores can be amazing.
That was always the limiting factor that stopped a slann being very powerful, despite his possible 13 dice a turn (using a p stone) he still tended to have only 1 or 2 must dispel spells within the lore he chose and the skink priest never added any such spells to the mix.
Now a slann + skink or slann + slann might be able to cause a lot of damage.
I can't wait to find out the actual spells in each lore.