what about giving each weapon a new value called "energy consumption"? Each engine size has a specified "energy output" and each weapon has an "energy consumption" value. As long as you are below the "output" with your "consumption", everything is fine. But as soon as you exeed your "output", the reload takes longer. An additional penalty could be a slowdown of the mech.
For example, a "300 sized" engine would have an "energy output" of let's say 300. If a PPC were to need exactly 150 "energy points", the mech would be able to have 2 PPCs in reaload, without suffering any consequences. Of course he still would be able to mount 6 PPC, but if the reload rate maybe tripples because they need 3 times as much energy as the engine provides (6*150 = 900, 900/300 = 3) where is the point?
It's just a rough idea, and real numbercrunching has to be made to make it work, but I think it would be a nice additional handwheel to adjust balance.
Of course I'm pretty sure, that people will tear this idea appart in seconds and it probably has been around before, but nevertheless I'm interested in opinions.
