Mixing RED with Super16? Good? Bad? Or Ugly?

[eraserhead_in_time]

Hey guys,
I'm involved in a project with fairly decent budget as 1st Assistant..
I was adamant on shooting the whole thing on RED however, the director (also the producer) has some depth issues with RED (and even Canon 7d) so he wants to shoot action sequences and ext. on RED
and for INT. he wants to use s16 (blowup)

I want to know if in post prod. footage shot with diff cameras can be matched well or not?
Also, Is it a good idea???

Any input/advice would be welcome

Thanks a lot