Hmmm. The evidence seems to suggest that your buddy was using incorrect rules, you're accidentally exaggerating, or I misunderstood you when you said he was "10th ECL" - I'm not sure which. I'm assuming you mean 10th lvl including ECL.
Let's take a look at the class; you can find it most of the way down the page
right here. He needed a +5 BAB to get into it, so if you folks were using the +1 ECL half-ogre then he'd qualify once he was a 6th lvl character (5th lvl barbarian.) That means he was a barbarian 5/warhulk 4, was using
mighty swing, and had a BAB of +5 (so only one attack a round.) Alternatively, he was a bbn 6/war hulk 3, had two attacks a round at +6/+1, and
didn't have access to
mighty swing.
Either way, this guy is getting only one attack a round over three spaces: either at +5 BAB with mighty swing, or using a full round action to do a great swing at +6 BAB. Unless his ECL is 11th, he isn't swinging at every square around him no matter what.
I've thought of one other rules error that might have occurred.
Each successive square chosen must be adjacent to the previous square and have line of effect from that square. Trolls are large creatures that take up a 10' x 10' square. Since he can only hit three adjacent squares, at most he could only hit two trolls standing right next to one another.
I'm thinking it isn't accurate to call a class over-powered when there's a rules mis-call.
The moral of the story might be: never allow in rules you aren't familiar with.