I'm having a little trouble following your math. My calculations show an average(mode) 16th level character as having 12 + con + (level-1) * 5 hit points, for a total of 90 hps(using 13 as an "average" con score). An average defender(give him 14 con to start, have him increase it every chance for 18 by level 16) will have 123 hps, and while he's going to pull the mean up more than the controller pulls it down, I find it highly unlikely that it'll get as high as 120. I don't have the Earth Titan's stats, but I was under the impression that there was some spread between the ACs of various 16th level characters. Is the 40% hit chance against defenders, or against an average based on what armor, stat, and enhancement bonuses are probable for all level 16 characters?
If he's got a much better chance of doing solid damage to another character, he might be willing to take the Combat Superiority basic attack or the Divine Challenge damage. Given the large amount of hit points elite brutes have, those might not be much of a deterrent.
I don't have a monster manual handy, but I was under the impression the brutes were glacier-like fighters: easy to hit, very tough, do pretty good damage, but connect relatively rarely. AtomicPope points out that artillery, skirmishers, and lurkers seem to be the big damage dealers.