25 and 45 on two bodies w flash on each enough for wedding reception

Two bodies, one with a wide and one with a moderate tele is old school, and works very well.

Depending on location I might prefer 12 and 45 or 12 and 25; getting close and into the middle of it makes pictures so much more lively.

Not sure what bodies you have, but with the OM-D I would skip the flash if ISO 3200 could do the trick. Yes, it would give a a number of 'moved' pictures, especially if things go wild (dancing and such). But it would capture the mood better. Or perhaps just a flash on one body (I would pick the body with medium or longer focal length).

Make sure to use different length neck straps, one camera high, the other low hanging.