Originally Posted by Retro Grouch

Just keep doing it.

A tandem has twice the weight and twice the power so, if everything else is equal, it should ride about the same.

Everything else is rarely equal. In fact, a common reason many teams ride a tandem is because, just like you, they are riders who are not very evenly matched but who want to ride together. I think that the more you ride together on the tandem the more those breathing and cadence issues will even out.