Synergy is different for every listener, dependent on his ears/tastes....
When a guy says "My dealer did all the synergy for me", he failed to understand that the dealer’s synergy picks would not be the ideal synergy items for his ears/tastes.
A ’good’ dealer would just let the customer pair different things he carries, let the customer listen to such pairings and have him decide what appears to be synergistic or not.
A ’not so good’ dealer’s usually trying to move stuff that never sells or trying to sell stuff that gets him the big margins... when he claims to do "synergy picks" for the unsuspecting customer.