Roll with less resistance, or "faster"? All things being "equal" as you say, the 26 in wheel bike will require more pedaling and faster pedaling to equal the same wheel-inches of the 700c bike. But in reality, things are never "equal." You might not want to pedal a 700c bike in as high a gear compared to the 559mm (26") bike. Smaller wheels=less rolling resistance (the principle behind Moulton's 18-in wheel bikes). So the smaller-wheeled bike might seem just as fast. Moulton uses large front chainrings to compensate, sometimes as large as 60t, and you could also with your MTB, if your chainstays will not interfere. Most MTBs have relatively small "largest" rings, usually 44t or 46t, so the top end on a typical 26 in MTB usually cannot match top end on a typical 700c road bike.