I don't know whether this can survive long enough to run 3 tons of ammo, but at least for my jagermech 3 tons of ammo is bare minimum.
With less than 3 tons you won't feel free to shoot, so yep, it's are minimum. That being said, I don't want to be rude but a standard engine 100 is stupid. Going XL allows you to upgrade to 170, which is still slow but at least playable (in most cases, XL170 is the best engine for crazy heavily armed light mechs)
You're forgetting about armor distribution. The reason for going with a standard over an XL engine would be so the CT is the only part with an engine. The original and your version both have only one point of armor on the left torso and left arm. On the original that would be fine because there is nothing in those sections. Your version turns that into a killshot.
Héhé, yep, I totally forgot to redistribute the armor (here is one possibility)(derived from my gauss build, wearing much less armor). But it does not change my point. The OP's armor is ingeniously distributed, but it's way to slow. From my experience, the XL170 is the best engine for uber-armed light mechs.
