Also, Jesus Christ, you kept the Mecha? Those things with negligible maneuverability benefits, made needlessly large and complicated pathetic targets that are either too heavily armored to move or too lightly armored to be of any use at all. Ruthless inefficiencies aside, they are just strictly worse than tanks supporting infantry, which fulfills all roles needed in modern combat.

The moral of the story is, in space, you are not going to get hit and live, at least not nearly reliably enough. So, you want the most boom for the least dollar. For example, strap an engine to a nuke, build a few hundred of them and win the space war for 5% of the enemy's expenditure, seeing as the things go at measurable fractions of lightspeed.