@Darkfox
I meant the MDMs on the assault tank are a heavy tradeoff when you want to use a walker instead. Against Scions, they rip incoming maulers to shreds (in conjunction with the blast cannon at range) and the splash or direct hit against a warrior is admirable. Not to mention shelling the bapoop out of the enemy base from afar.
If you want to trade that all in for 2 of those fearsome cannons, double the health, and some healthy pummel for the dirty work, though, be my guest
Either way, service trucks aren't really good for retreats. They don't like being reversed into and form a nice cushion of trapped. Easiest remedy is to place nav beacons on your retreat path as you progress forward. Send the trucks to the closest point to allow some reverse, although if they do get the jump on you, expect to fight it out because moving that much tank anywhere very fast is almost impossible.
Yes, they can M-Curtain or Mitts you, but what happens if your rocket tank friend is sitting next-door?

Your strat guide, if it doesn't already, should include how to be a serviced assaulter, rather than assuming people understand their responsibilities. Sure, it is easy enough to say move forward and pwn anything that moves and even what doesn't move, but there is more of an art to it then that. I've had my serviced assaulter charge forward of the group too far and needed to recall him for base defense, but it was too late. That is the thing that can be avoided with some good reading, along with how to properly escort the assaulter.