Anything wrong with giving clerics the summons they have as mounts?

[Bobbity]

This thread refers.

Clerics need a lot of skill points until they can benefit properly from a firegon, earth elemental or ice dragon.  They don't come for free. The benefit is usually barely worth the SP cost. Should clerics be able to mount these summons? (And yes, I know how ridiculous some of them would look.) Considering they natively have Mana Shield, which goes with mounts, is this game-breaking? Discuss with ice-cream, pizza and reasons.