Is a husband really meant to be dominant to his wife? Really? Maybe what you were intending is that many men believe this and so temporarily giving it up allows them to access new places in themselves, potentially leading to greater pleasure. Getting rid of your hang-ups and preconceived biases certainly does make room for exploration, which will likely lead to better sexual satisfaction.
Yes to the visual appeal of seeing someone you know well from a perspective that you don’t get to see when you are in the action; yes to realizing that seeing your partner with someone else doesn’t mean you are losing them; yes to spicing things up by getting out of your usual lanes and roles with each other. Nothing will put you in the present more than having someone else in bed with the two of you, and the men don’t have to be intimate with each other in order for it to be incredibly hot for the both of them. Guys need to check their possessiveness and jealousy at the door, but if able to do so, I highly recommend this arrangement.