One problem with that: Charging the Carthage would be just as effective as charging the Imperieuse. In both cases, the Imp has enough time to set up full-power beam shots (To say nothing about Hydra) at the charging vessels.
Really? I distinctly recall noticing the Altan Orde bump into the side of the Carthage while turning to face the Imperieuse.
Excepted that in FS, Ramming Does Not Work, as said above.
Sometimes it doesn't, sometimes it does. The GTD Goliath was destroyed by ramming during the Terran-Vasudan War (FS1 tech room description of the PVF Anubis).
Something happening a couple times in a game does not make it an inviolable physical law of the game's universe (not even if it's on tvtropes).
EDIT: It's also worth noting that Silent Threat: Reborn is canonical within the backstory of Blue Planet, so we also have to consider the Hope's kamikaze attack on the Hades. The Hades wasn't destroyed, but the damage done to its engines allowed the Soyakaze to destroy it before it could start Vasudan Superlaser Bombardment Holocaust Part 2: GTVI Boogaloo. I think that qualifies as ramming working.