Halo Wars: Definitive Edition

This works really well if you play on easy, and avoid killing all the enemies on your way through with the Grizzly Tanks! Just speed through, just killing some that get in your way, get across to the other side to rescue Forge and Anders, and then wait on the other side of the bridge.
Keep your Grizzles away from the other side of the bridge so they don't kill enemies crossing the bridge once it goes back up.
Because you didn't kill all the enemies on the starting side, you'll have a lot of them immediately start crossing the bridge as soon as it's activated. Simply wait until they are about halfway then hit the bridge controls(press on the thing Anders was standing next too and press ) and you should get quite a few. I got at least 8 groups doing it this way!

After using Anders to repair the light bridge, keep your units away from the bridge and let some of the covenant people start crossing. Once there is a few groups of covenant infantry crossing the bridge, click on the console that you repaired and turn the bridge. I waited until there was more than 5 covenant units to be safe.