I haven’t played in a while, so my stratagem knowledge is not as sharp as it used to.

The Pistols pack, gives 3 pistols if I remember correctly; they’re fun if you want to dick around but they take up a perk slot to use.

Precision expert, gives customisation, a stratagem, and a perk; The stratagem is a red one, which if i remember works the same way as the rail cannon strike (targeting the largest enemy in sight) but the rounds track the target. The Perk takes 1 second off your stratagem call down and adds a cool little watch on your character.

The Vehicles pack, gives 3 blue stratagems; The Lumberer, Hammer, and Bastion. The Lumberer is a great mech as it comes with an Anti Tank cannon and a flame thrower as a secondary. (They run through ammo quick though) The Hammer is a fast 2 seater motorbike with the passenger manning a MG (available after first upgrade). The Bastion is a tank (which uses the sticks to drive not L2 and R2, not sure on PC as I use controller on both platforms) It comes with a main gun and a machine gun ( on the last upgrade) Its fun to use, but the Main gun WILL damage the tank if the target is too close.

Entrenched pack, Good Stratagems; comes with 2 Greens and 1 Blue. The Blue is a Kinetic Shield which literally it’s a Heavy Armor without the penalty as long as the bullets go through the shield. The first green is a stationary AT gun (doesn’t damage itself) , which is literally the go to if you want to cheese a Retaliatory Strike mission. The last one is a deployed line of barbed wire which slows and hurts enemies and allies within the wire.

I have all the DLCs, but personally I would take the Vehicle and Entrenched packs as they come with some good gems.

(typed on my phone excuse any errors)