To be fair, it's historically not a great circuit for them (they were scary fast in sector 3 at Barcelona though... so that doesn't bode well for Ferrari/RB)

They won it four times in a row recently, and they have the best car in low speed corners this season.

Ferrari, on the other hand, could be having to fight with Haas at this rate. However, the only projections I've seen used S3 data from before the testing day and Ferrari apparently have new suspension (Which is very important around monaco)