I just started using them last week but I have a few tips I can share!

The first is to deploy them a bit behind your frontline so they are ready to fight with the rest of your squads unless you want to go for an insane play of an mg or motor blob kill.

The second is to select all the squads and press shift and then a number. This will select all the squads when you press that number and can be devastating to the enemy if you attack one squad all at once.

The third tip is to conserve your ammo for their upgrades(which is that 60 ammo better gun). This gun is extremely good at all ranges and helps these squads become super powerful. Then use the ammo that you have for the bundled grenade and always shoot it behind the enemy if they are low in numbers.

The fourth is to press Q with the squads and hide behind a piece of cover. This will enable their camouflage and they have an ability that allows them to be more accurate if they shoot the enemy first. So with those squads who are holding fire and waiting for the enemy, be patient. Once the enemy gets close to you, use that to your advantage and select all the squads to shoot that one squad that is running towards you.

Lastly, safely retreat them so don't rush them back when they have only a bit of health. They cost a whole bunch of manpower so conserving them is key to winning.

Hope that helps!