Look, I like the balance at the moment. In-universe, the 'Mechs are meant to be that bit better. In movement terms vehicles get specific advantages depending on motive type & terrain; 'Mechs have all-around mobility, plus jump jets, plus orbital drop, but that doesn't give them that much more superiority.
Depending on the vees you take, and with the current crit mechanism, tracked vees run the risk of becoming pillboxes, but are still potentially useful; hovers & vtols pay in fragility for the potential for blinding speed, and wheels pay terrain limitations outside urban maps). So IMHO yes, they are weaker than the equivalent tonnage of 'Mechs, but fit within the 'metagame' which says 'Mechs rule.
W.