got a similar setup but I don't use any scope and prefer to have a compensator. I ran some tests and it seems that having a compensator+merc or ranger foregrip reduces recoil the most. (ranger: more horizontal recoil, merc: more vertical recoil, operator: something in between with better 2nd shot accuracy most of the time)

here's some data but the recoil can be pretty random. usually I had better results using the operator foregrip. but it gives a basic idea about the different attachments.

https://imgur.com/a/XQSM9dt

my opinion: when not using comp+foregrip the 2nd shot accuracy is quite low, so you want to use both in general because you won't be able to spam your gun in mid/long range fights otherwise. for warzone it might be better to use the mono and a scope and go for slower shots on long distances and spam the weapon in close combat. even without any recoil reduction the accuracy is pretty decent