Sean-
yep, I am sure. Fought the same battle 4 times. First time, used "Dirg" spell with my 9 death shards, instakilled a "strong" party for 1 exp. My sov had the 10% bonus... and still got 1 point.
Second battle, used the spell that reduces constitution, strength, etc.. just 1 time, ended up with 17 for the sov, 14 for everybody else (and 1 of my champs fell in battle).
Third time, used that spell twice. Cleaned up. 1 exp. for everybody.
Last time, fought with no death spells. Sov had 48, 2 champs bit the dust, the rest got 42 exp.
THAT is when I realized how much exp I was missing--no wonder I was having to wait until endgame just to get my sov--with the 10% feature--to level 9!