OK, i tried them as standard/support for front units, without any bless. Works fine : combining them with a Fanaticism spell as Twan suggested results in the C'tis armies routing only when they are 90% destroyed
I noticed regular losses amongst the Sacred Serpents when mixed with other units, mainly due to ennemy archery. But as they're pretty cheap, that's not a great deal. Nevertheless, putting them in rear area units is an option I might consider.
So : no bless strategy for C'tis... Well, that will be my first "no-bless" game also
