[Mightypeon]

The luck guy is definitly working for me, my guys turn a bit green and get luck in the attribute list.
I would be a bit in favor of replacing the really strong buffs by a bit more minor buffs that still could make sense. This would also encourage to thugs these commanders out, as their main use would no longer be the onbattlespell.
Rush of Strength comes to mind for example, as would Fanatism.
So, as a sweeping solution: Reduce costs for both of the Knights, make the cheaper one autocast rush of Strength, and the more expensive/higher research one autocast relief. Other options could be quickness (which would further encourage using them as thugs, as you would have to place them fairly frontally).

I actually dont neccessarily think that Gaias Blessing as on battlespell is overpowered in itself, it would propably be good for dominions if more nations had access to it. Especially the "Might" nations. Rose Ulm to an extent reduce the Dominions Paradigm that "Magic always wins" to "Magic usually wins", which is not neccesarily bad in my opinion.