So here I go again. I'll give you a few ideas for both primary and secondary weapons.
1. An electromagnetic emitter. It requires a certain amount of exposure to the enemy to disable them, but it allows you to completely or almost completely avoid collateral damage (the same goes for sonic weapons, but I don't know how it would work against unmanned vehicles.)
2. A large-caliber howitzer, 155 or 203 mm, something like the cannon on the M551 Sherridan tank. Its short barrel allows you to fire shells over buildings and terrain.
3. I BEG YOU, PLEASE TAKE THAT SMOKE AWAY FROM THE AIRSTRIKE, JUST NOT THE WAR THUNDER AGAIN. Use IR beacons to guide missiles; the crawler can certainly warn you about it.
4. Perhaps we could add something like the existing LOSAT to the primary weapon slot.
5. Perhaps something like a swarm of homing mini-missiles.
6. A plasma arc controlled by an electromagnetic field, with a limited radius but a fairly large area and massive damage.
7. Drones with machine guns and kamikaze drones in the missile slot. They can follow terrain and are homing, but their slow speed makes them susceptible to being shot down by machine guns and autocannons, but they can't be intercepted by APS.
8. Orbital strike with a railgun or laser.
9. A machine gun turret is cool, but how about a missile turret like in Helldivers?
10. Heavy lasers and plasma weapons. I'm not sure about its uniqueness, but it's possible to make a heavier, armor-piercing laser that would instantly penetrate walls, but it would fire in short bursts and require cooling time. Plasma weapon: fires a magnetic canister filled with super-heated plasma. Upon impact, the canister is destroyed, allowing the ultra-dense plasma to escape, creating a powerful explosion with an incendiary effect.