lol fair enough. You could have been more clear
or said something like "if his incline moves his flat moves as well"
in that regard though I tend to agree with Naparm. if he's getting 1:1 out of incline:flat, it's a lot harder to move an incline bench than it is a flat.
for someone who hasn't done much/any incline though, you might get a 0.5:1 or something like that eg incline goes up 10kg, flat 15kg which would be better training economy
speaking to a few guys over here (and Bostock at ESP) they all have a bench-related movement that they know if that improves, their comp bench will.
eg Mark Bell floor press, Brandon Lilly 2-board press, Bostock floor press