That 88flak approach could inform how things are balanced here. Multiple thrusters is definitely a no, but right now, there doesn't really seem to be a point of LFs and HFs. Rather, their weaknesses vastly outweigh their strengths, barring a few edge-case scenarios.
But as to the designations, I really do agree that "VHF" is a holdover from when there was only Eagle, Titan and Sabre, which were positioned as upgrades from the Falcon, Centurion and Stiletto respectively. But now, the roles are different, it's not a straight upgrade.