Blessings balance?

[Meglobob]

Newbie question related to blessings.

I have a rainbow pretender, lvl 4 archmage, in all forms of magic. The strategy being he goes from province to province searching for magic sites, lv4 gives 100% chance of success I believe. Is this a good strategy?

When my priests bless my sacred troops, it looks like I am just getting air shield, 20% missle defense. Why am I not getting the other lvl 4 blesses? Or am I and I am not noticing? If I am getting just air shield, why?

This is currently in the Dominions 2 demo, other than changes in bless powers, is the bless system still basically the same in Dominions 3?

Thanks in advance to anyone who shares there wisdom.