Strategies for Troops (Apocalypse)
Early in the game, it can be a beneficial tactic to set apart a few agents as a 'stun squad'. This squad carries stun grapples and stun grenades and is tasked solely with capturing aliens alive. Because they'll be getting up close and personal with brainsuckers, it's a good idea to comprise your stun squad out of androids.
Once you've got a few aliens stunned and down, keep your stun squad near them. Real-time makes this much easier, as you can set them for Aggressive and Auto-Fire and they'll automatically re-stun any aliens that try to stand up. Using a separate stun squad made up of three androids with twin stun grapples and grenades in a fresh game, this editor was able to capture alive an Anthropod, Spitter, Hyperworm, Multiworm, and Brainsucker all within two missions following acquisition of the Bio Transport Module.
Heavy Weapons & Real-Time Mode
Heavy weapons, such as the MarSec Heavy Launcher and the Dimension Missile launcher should be used with care in real-time mode. Personally, I recommend avoiding missile launchers entirely if possible, as one brainsucked agent in Distruptor armor with a dimension launcher can cause some serious pain later in the game's stages. Unfortunately, the game's AI doesn't seem to check friendly fire prior to using weapons, and you can easily end up destroying your entire squad if you don't keep heavy weapons reigned in. If you must use weapons like these, this editor recommends keeping all of your "heavy weapons experts" in the same squad, setting that squad to 'No Fire', and manually ordering them to fire when it's tactically sound to do so. An excellent example of this is when you're tasked with disabling parts of alien structures later in the game.