Sinuous Trail S rank with 2 friends HELP

[Excal]

My 2 friends and I just got the game and we've played the map nonstop stop like 7+ hours and over 100+ games.... we can't seem to S rank it. ♥♥♥♥ goes bad and we try and go slow, mirror gun, gas, flash, damn this map is so hard. I just instantly restart the map when someone dies which happens very often and we are trying Hard.

So far our strategy has been going through the left side of the building and clearing the bottom and checking outside, Then going through the roof/2nd floor. The main server room and the 2nd floor room are the hardest it seems and we always die there or have trouble. For equipmentm, im a mirror gun guy with a pepper gun, friend 1 is a breach-shotgun with beanbag shotty, and friend 2 is a pepper gun with gas launcher. I have tons of gas grenades too.

The map seems almost impossible as there's so many angles and doors for enemies to rotate. The map is a mess with so many doors and connected hallways enemies just go around town and boom you're dead.... The closest we've been was 7/11 suspects.

Also, do we lose S rank if an enemy kills one of their own through cross fire? I cuff one guy, guy across shoots at me and kill his friend

[Reb Militia]

If anyone dies yes you lose S rank even if killed by another enemy

[lowBlow]

Ive been trying to solo S rank it for the past 3 days. Best i can do is 9/12 suspects.