Um... 'Big mech' generally tops out at 100 tons, aside from oddities like the Omega and *shudder* Ares, neither of which are so uber that you couldn't take one out one on one if you're careful. Further, not all of the leaders of the Successor States are even mechwarriors, and generally are rather far from the battlefield, protected by the elite of their own fighting forces (Davion Brigade of Guards, Otomo, etc.).
Further... Loot drops? Really?... 'Best tech' is Clantech, which wont be around for another year. It's a Mech, not a level 85 Paladink (yes, I spelled that as I intended to). +Uberleet armor doesn't exist, neither do Tier 8000 weapons. The best finds it way to the front because it needs to already in the setting (or it gets salvaged from what you manage to fry), and frankly, it should be about the skill of the man in the mech, not some random super special naval-grade-but-mech-mounted cannon that outdoes whats been established for decades as the best already.
Honestly, it's Mechwarrior, not World of Warcraft or Chrome Hounds, lets stick with that. An evacuation Dropship might be an idea for a 'world boss' of sorts, but at the same time, the leaders generally exist as plot devices in this setting, not active, killable, infinitely respawnable bosses... Not that an exploding Dropship would leave anything left to salvage. In the end... No, sorry, too much of a collection of generic MMO devices for my tastes.
Edited by Davison, 31 August 2012 - 01:45 AM.