I'm picking Albon as a benchmark because 1: it's Williams vs. RBR 2: I'm a Williams fan since '92 and 3: because he's the one Perez replaced. This table would also be true for a great part of the f1 grid.

Monaco:
ALB 13 - 20 PER
Spain:
ALB 18 - 11 PER
Canada:
ALB 10 - 12 PER
Austria:
ALB 10 - 15 PER
UK:
ALB 8 - 16 PER

Average: 11.8 - 14.8 in two cars on the opposite sides of the table. That defense against Lewis, although spectacular, can't be worth that much after all this time, can it?