This is a great idea but nearly impossible in the 25% Lord/Hero allowance before (50% makes it more plausible to see these days). Yes, you'd have 327pts, but then you'd still need a BSB (unless you made one of them the BSB, which bumps it to 352pts), but then you're cutting into Firebellies and Butchers (for possible "butcher-tax" if wanted).
If you were intending to have two Bruisers AND a separate BSB, you're looking at a hefty 462pts (before kitting, IIRC), which is a HUGE amount of points for 3 models in any game less than 3k. You could technically run this within the confines of 2k points, but really... so expensive, when, if you want to look at straight numbers...
Tyrant full kit - 322 - 5 S7, WS6, 5W, 1 Stomp
Two Bruisers with kits - 327 - 8 S7, WS5, 8W, 2 Stomps
7 Ironguts w/Champ upgrade - 311 - 13-22 S6 attacks*, WS3, 21W, 3-4 Stomps* *
depending on deploymentStatistically speaking, you're still going to do more wounds overall with the Ironguts, unless you're going up against a super-beefed up enemy lord, in which case you're gonna be dead with
any of the options above

Plus, the difference between S7 and S6 is very little in most scenarios, again with the exception to super-lords or the added exception of 1+armor knights (that extra -1 to armor save could help!).
Ultimately, you're looking for more dice to roll, because more dice is ultimately more odds to succeed. But, at the end of the day, if you're planning on just having more attacks to take care of business (i.e. enemy troops), Ironguts'll win it out in the end. If you're looking for a challenge-monkey, I'd prefer the Tyrant due to the slightly better statline and the ability to
really kit out (well, for Ogres, anyway). However, if you want to make the crazy character wall with Beasts-bubbles everywhere, totally do the double (or even triple!) Bruiser list.
38 Gnobs! Almost on my 4th Pack of Trappers! Exciting
Gibblet, Nibblet, Crunchybit, Snorti, Lullzee, Wakezee, Wardler, and Primo! (For sharing the Forum Primer to help out a new member! )
New book WLD: 21/11/3 - Got trounced by one of the "Khaine" elf armies... Stupid new rules...