Unusual dealer recommendation for rears

Hi...just bought new rears with side firing tweeters and forward firing midrange which has less bass response(80hz) than the forward firers I had before (40hz). I missed the bass response and the "bigger" sound I had and as the 2 sets of speakers are efficient(though slightly different sensitiviy rating) dealer recommended hooking both up to my rear monoblocks...have done and it sounds better...please tell me whether you think this is a sustainable and wise solution or a big no no...thanks