Machine Spirit + Ram?

[jy2]

The difference is that PotMS says "can always fire one more weapon than would normally be permitted". It's general in scope and applies to all situations which would affect the LR's shooting. The Lumbering Behemoth rule makes an exception for 2 and only 2 situations - when you are stationary (kinda stupid since if you're stationary, you can already fire everything) and when you move at combat speed. Everything else, you still have to fall back on the default rules. So if you're stunned or popped smoke, you still cannot shoot.

In other words, PotMS is very general and thus applies to all situations. LB is very specific and only applies to 2 situations.