This is a moderately easy mission on Expert Difficulty, depending on how many troop losses you are willing to sustain.
Also, if you ended Mission 1 - Wolfheze with more than 50 points of unit Population, you may be initially limited in what you can field (artillery pieces are mostly transferred to (yellow) allied forces).
In the following pictures, we show the units we ended Mission 1 with, and the troops we began Mission 2 with. Since we started with 54 population and the cap was 50, and our gameplay paradigm did not allow for recycling units just to make new ones of the types we wanted, we had to play with the units we began with. We did end up saving all units (no losses), although in the process we had to experiment with various tactics against the Tetrach Tanks.
Part 1 - Rescue the AA Gun
Send in your vehicles to protect the AA gun nearby. There are two snipers, making it tricky to send in infantry. If you fail to protect the crew, you'll have to man it, but it's really only useful in the final defense phase of the mission.
Part 2 - Find Snipers
Move up the left side and take point with vehicles. Unlike American vehicles, the lightly armoured vehicles look like they should be immune to infantry fire, but they aren't, so retreat them to be repaired. For now, keep sending them ahead to find and kill snipers until you receive the medal.
Part 3 - Anti-Tank Enemies
Anti-Tank guns and some medium tanks are further ahead in the map. On Expert difficulty they can one-shot your vehicles. If you see any, immediately retreat and mortar their position or send in infantry.
Against Tetrarch Tanks, your best bet for minimizing losses is actually to swarm them with Infantry. We chose Defensive veterancy upgrades for infantry and almost all squads have a Panzerschrek (from Mission 1). Try not to engage more than one at a time. They will also quickly flee, so that can help as well.
Part 4 - Paradrop
After taking the final strategic point, there is another paradrop. Retreat all units to the artillery line and just hold out until enemy infantry and jeeps stop coming. You don't have to hold any strategic points and the enemy does not try to capture any.
You can destroy some of the initial drops of infantry, but it is better to simply pull back and present an organized defensive line backed by powerful artillery.