As for how you outsmart 5 plasma/laser mercs, shoot them with a rocket or two, and have a friend burst twice with an LSW, problem solved.
For rocket launchers, some one is pretty much going to have to take one for the team... once that happens, hit them with a rocket or three, than burst with an LSW as before, or spawn in a cheap slave squad behind, than step out while the snipers cover you.
This has been explained a number of times, FOnline currently is like rock/paper/scissors. Mercs beat snipers, snipers beat big gunners, and big gunners beat mercs.
As for people using mercs in TC, the way people use mercs, are for ambushs, i blew the crap out of a little level 7 merc leader with a rocket the last time i got ambushed by mercs in a TC fight, he was a alt, and probably a proxy, if you allow people to have 6-8 mercs with 300 speech, guess what, people will make those ambush alts and give them even more mercs, and they'll still show up with surprise butt sex just for you, but this time with more rocket mercs or plasma mercs.
As for using a group of people with rockets and sniper rifles to use mercs fully, that's not the best idea, those snipers won't last if they have to close in, sooner or later someone camps, and a sniper cant rush a building and hope to survive for as long as a BGer could, which is why you have the bursters up front, to handle mercs and militia, and rush with, for when you're pushing for ground.
Oh, and i've created a build to show you, that it'll just delay the merc leaders, you can still make a useless character for merc handling, it'll just take alot longer, but still do able, if you level off ODM.
http://www.nitue.net/fcp/It should be "Post Wipe Leader". have a look.
-Ulrek-