IMO, yes. Most tours line up on the pier about 1/2 hr. before the start time. That would give you 15 mins. spare time. Mexico does not run on "American time". It's rare that the tours there are exactly punctual. It's very, very common for them to run late.
That said, you'll have a little bit better chance making both of them since they're independent tours, but is it worth the stress? You'd REALLY be cutting it close and I think you'd be sorry you tried to do too much.
We've found that once we're on the ship, something comes over us and we're never as gung-ho as we thought we'd be. I'd choose one of them and do that instead of hoping that absolutely nothing went wrong on the first tour to slow it down. JMHO.