Again, that only happens if you get a very good disable from their flanks, which as stated, is mostly not the case unless you catch your enemy completely off guard.
Their ally can still kill you while you can't realy kill anything nearly as fast and rely on your ally to do all the killing. A sucessful quick kill with a Heavy carronade for example can only happen with a coordinated ally charing the same target as you and focusing them down fast while you use your superior burst damage to get a quick advantage for a little while, if anything goes wrong your quick kill will suddenly take 4 times longer to get.
Matches in which there is some slightly major skill difference between players simply don't count, I mostly see level 4 and 6 pilots in the enemy team, who are mostly just not experienced anough to deal with the disable, not the disable being actually effective.
And any ship is doomed if you focus their balloon long enough, it's not only the Pyra, yet, you mostly won't have a good chance to do so cause:
1) focusing on one balloon only is pretty bad since you leave the other enemy afloat and able to kill you or your ally.
2) an experienced pilot will probably just let his ship slide below your arcs, repair and then dodge you, which means a lot of precious time you lose because of horrid arcs.