It would've been, wouldn't it? Q_Q
And Riker as both Captain and First Officer, now all they'd have to get rid of was Mr. Dong-Faced Jar-Jar and the show could actually have been insanely amazing.
I'd not be so sure, sadly. For me the biggest problems of Voyager came from the creative crew not knowing what they want from characters. Janeway wasn't the only problem, just the one that was the most visible because she got to call the shots as captain. They had to write Kes out because they wrote her in a corner she could not come out of, they kept Neelix in to do kid stories (well, at least Naomi didn't save Voyager every week, but she sure did grow quickly. Good they made her half-alien to explain it, probably an oversight ) and Chakotay starts dating Seven because... because. So Seven can have her romance arc to show off how much she's... eh, no, I need to stop. Heh.
Needless to say it's far more likely that they would have simply messed up Riker as a character instead of making the show awesome. So it's probably best that they had no established character (Tom Paris doesn't count, it was just one TNG episode and he's just a suspiciously similar substitue after all).