The arms race is alive and kicking int he 57th century!
Make something strong, I'll make something stronger. We are better at making bigger guns than we are at making bigger tanks (tho bigger tanks have their own problems like breaking bridges or sinking in mud).
Do you want that to be the case in YTU? If so then go for it! I've given up hoping for consistency in rules written by a variety of people over a period of many years with no central guidance. I hope Mongoose can forgive me for saying it on their forums but that's my take...
The danger with this discussion tho is we're getting back to the need for MgT to have a unified design process for weapons and vehicles that uses one scale for everything. Oh wait, I've said that before
First, I think Mongoose has done an amazing job. The work required for internal consistency is a difficult one and you're always trying to balance the benefit of adding content, with the work required to vet every rule/option/addition in relation to the previously establish stuff (PS Matt, I'm available to moonlight as consistency-editor lol).
Second, I think with the new values in mercenary, theyve done an AMAZING job. In my current adventure, the semi-amateur merc company is running around with advanced combat rifles, with access to RAM AP grenades, Gauss weaponry, Magrail, and have just gotten their hands on Advanced Boarding Vaccsuits. When you compare this stuff, you end up with a fairly even exchange between protection and firepower. A good hit can instantly make you unconcious, but more often than not, you need 2-3 hits to go down. Prior to Mercenary second edition, the DSAP ammo and so on basically ended up making most armor completely redundant.
Thirdly, I dont think there is a big issue with the vehicle Fusion X/Y/Z or Rapid Fire Plasma guns and so on. These things weigh tons and arent' being carried around by some dude.
So the only issue I have is with these 10-12 kilogram babies