You’ll notice that Alpha team has been ordered into line formation to maximize firepower while bravo team is still being ordered to move from cover-to-cover on the flank.
If a man goes down, you can order a medic to move near the injured soldier. Then use the action menu of your wounded soldier and order him to “Heal at Medic”. Keep your people healthy. If they remain injured, move them back to a support / overwatch role.
Depending on the game settings difficulty, whenever a friendly unit sees an enemy it will appear on the map. You can then use the target menu to assign team members to engage a specific target.
Once all known enemies have been eliminated. Then order one team to cover from high ground, and send the other team into the town to sweep and clear.