Re: DS9/VOY...if it happened differently...
There was also Sisko's friend who worked in the DMZ (whose name I cannot remember!) that they could have had in place of Chakotay.
Cal Hudson played by Bernie Casey. That would've been interesting as he certainly wasn't a dull character, whatever else. Sisko's former friend would've been something of a tie in to the series.
"I was never a Star Trek fan." J.J. Abrams