A few tips:
-Use all of your equipment in TME. Droids, Radar, Shields and Ewebs make a massive difference when fighting through the streets.
-It's important that you get a sniper up into the high ground. You'll then have a massive advantage as you'll be able to see enemy movement. Get the sniper to shoot and spot at the same time.
High Ground locations: Tower next to the market, Tower next to Commerical District, the two Jabba Towers.
-If you see the enemy on the radar, take a second to stop and work out wheres best to 'block' him off. The idea with TME is you can easily counter the enemys movement with a simply roadblock.
-Always stick with your squads, TME is not meant for rambos, and if you do rambo, you'll die and very quickly.
-If you do get lost, stick to the main roads. The alleys deeper in the map are designed as 'alternative' routes to each flag and will prove to be a faster route. I can travel from the Commerical district to Wattos in 23seconds.
-The further the Imperials advanace, the harder it will be for the AT-ST's to dominate. The streets get narrower and has more cover and more back alleys allowing Rebels to easily pop out and fire off a few rockets without ever being seen.