putting nukes on mechs would be a limited scenario thing but they could hypothetically infiltrate close range less detectable weapon systems into place for a surprise attack to take out nuclear response facilities.

for fighting in close terrain, i think slower mechs using traditional cover based tactics (modified to account for tactical and comms options and equipment specific to the mechs) would be better than super fast thruster mechs. in armored core you take no damage from impacting walls, but in real life flying a jet at 100ft above ground level is incredibly dangerous, let alone lower. i doubt a human could withstand the g-forces and pilot accurately enough to maneuver in urban combat for example without drugs or cybernetics, and even then the risk of crashing would be significant. thruster-mechs if we could build them would probably be better for aerial interdiction (missiles or aircraft) or for launching hypersonic missiles as a first stage launch vehicle. they could hypothetically out-maneuver airplanes (airplanes can't strafe and mechs can have thrusters basically anywhere) if not match their speed which could help them avoid anti-aircraft missiles. i could see them being carried by aircraft carriers or missile boats as close-range air defenses. maybe even as ground-based missile/aircraft defenses.

the non-humanoid design elements might make more sense on mechs that are semi-autonomous where the pilot more or less just guides and overrides, but even a humanoid brain-interface mech could have some kind of removeable, collapsible, or retractible wheel attachment for logistical movement purposes at least, but also i think skate-style movement with wheels or hovercraft on the feet/legs could be intuitive as well for humanoid control.