They are super strong. The same way that machine guns look great on paper until you deploy them and their AI tells them to shoot unnecessary walls? That is what bazookas do.
When I unlocked them I was excited, so much so that I figured that combined with my Brandenburg gate, maybe, JUST maybe factory troops were going to be big in Global Age. I spent about 7000 oil and trained 26 of them, 5 machine gunners, and a few supply trucks to keep them healthy. Then I sent them into a base and let them go. They started off wrecking the place, then I made my way into a few walls and rallyed them on the town center. Mind you, they were standing mere inches from it to begin with. They decided that destroying the town center I rallyed wasn't important. Instead, they walked back out of the walls they had blown their way through, past a few lv 9 towers and a mortar, and got themselves all killed. I'm guessing their tank detection range is huge and they work like archers in that they actively seek out enemy defenders. But to come off a rally to find a tank across the map? That's a problem. So yeah, my run with them was less than satisfying.
If their AI was improved, they could easily be among the strongest unit right now. Their DPS is really high for 4 troop space and they have enough health to survive a few hits. But you have to babysit them. And a rally every 30 seconds isn't enough babysitting.