Mating - Center between 2 holes

I am just curious how other people perform this task...

I have a piece of plate with drain holes in it. I need to center a stiffening plate underneath it between 2 holes. The width mate will not do this

All others I was able to use planes (symmetric mate b/c sheet metal), but this one instance will need to be offset to prevent interference.

What is the best practice to center this plate? (All I can come up with is to use a distance mate, but I'd rather not)