Merging 2 offices, What to do?

How would this scenario work out best for both parties:   One larger producer merges with a smaller producer, to form RIA.

The larger producer would do what he does best, prospect.  The smaller producer would handle most of the client contact and all of the investment decisions and planning.    

If merging the 2 books, how would you work out the percentage split fairly between the 2 FA's?  The way I see it the larger producer/prospector should probably get a higher payout than the smaller producer, right?  But what would be fair?  Any thoughts?