0% Infiltration is never something I do except when I want try for the fun. I did very low infiltration only twice, and getting very high or even highest enemy activity. So it's not much per experience that I'm answering, ha ha. Moreover for now I always "lost" those missions and at best I reload "only" 3 times to finish them.
In my point of view the highest danger is coming from number of enemies and map size. Last time I played the start was 3 pods at first turn including a 2 sectopods pod, 2 pods following the turn after. Or 2 pods at first turn (soldiers not concealed just moving to very close covers, even in back) including the 2 sectopods, and 3 pods at next turn. The good aspect of too many enemies is it generates many opportunities for AOE attacks but you need have the resources for that. Now frankly it was looking rather extreme, but I even had one of those mission where steam landing triggered a pod with 2 sectopods, thankfully in this case I had a good infiltration.
But it wasn't so much cramped at the start with a previous attempt, so I don't know. For now I'm still uncertain about the best theoretical setup. But definitely about some aspects and focusing on a very possible quick rude start:
- 6 sting grenades is the minimum, I would target more 8, and 4 Plasma Grenades through 2 last level Grenadiers.
- 3 Exo armor or WAR armor if possible, and the most possible with weapon upgraded to Shredstorm Cannon, those provided to any soldier not sniper/shinobi/commando with shotgun. A Technical or a Spark could replace one.
- 1 sharpshooter with Serial.
- 1 Shinobi with Reaper and serum.
- 1 Psi with Void Rift, if possible with Null Lance and /or Domination.
- 1 great Hacker and hacking setup including at least one soldier with red ammo.
From this base I'm not sure what would be the best setup. Just some points in my opinion:
- For me 3 sharpshooters doesn't look like a great setup, I don't see how such squad wouldn't be dead with a cramped start with many pods as I had the last time I tried. But I'm not an expert.
- OW looks good but I wouldn't expect kill most stuff in OW. The point is, in such mission in case you have a pause instead of moving forward you should better do few OW wait turns. So OW setup looks good, but full standard team OW is already a good bonus. So OW setup would be more a tactical choice than a necessity.
- 2 Specialists with at least one medic or two half medic, and at least one great Hacker.
So an example of team I would try target:
- 1 Shinobi with Reaper, Conceal. Warden Armor, Overdrive Serum. I hadn't any at my last mission like that, a Technical with Phantom was supposed to do the job but didn't much because at rude start I couldn't resist not use him. But obviously such Shinobi should help but I would be very cautious about awaking pods with the Shinobi attacks.
- 1 Sharpshooter with Serial, Death from Above, Damn Good Ground, Precision Shot, Deadeye. Wraith suit, AP ammo, Stock.
- 1 Psi with Void Rift, Null Lance, Domination. WAR suit, Shredstorm Cannon.
- 1 Grenadiers with Rapid Deployment, Protector, Bluescreen Bombs, Sting Grenades, Full Kit. 6 sting grenades, WAR suit, Shredstorm Cannon.
- 1 Grenadier with Sapper, Heat Warheads, Bluescreen Bombs, Sting Grenades, Full Kit. 4 Plasma Grenades, 2 sting grenades, WAR suit, Shredstorm Cannon.
- 1 Specialist with great hacking and more Medic oriented. Revival Protocol, Field Surgeon, Medical Protocol, Full Override. Warden Armor, Nanomedikits, Skulljack.
- 1 OW Ranger with red ammo. WAR suit, Shredstorm Cannon.
- Not sure for the 8th soldier.
- At least 2 soldiers with shredding shots either from skill either from ammo.
That's an ideal probably impossible to achieve, with at least 4 soldiers at max level, and a Psi very high level not sure it's even possible to have all those skills with only one Psi. Without to mention the highest level equipments, you'll probably never get that many.
It's also a setup from the point of view of high level enemies with a lot of armor and the guaranty of many mech stuff.