On first reaction, one would think the Cuban republicans
On first reaction, one would think the Cuban republicans may be able to win against the Spanish absent a US expeditionary force; of, if it does take the V Corps and the Atlantic Fleet, than - presumably - the Cubans will get a better deal than they received historically, in terms of avoiding the Platt Amendment, etc., and generally being treated more as a republic and less of a protectorate.
Which would, of course, have some pretty significant ripples across the Twentieth Century, in terms of US-Cuban relations specifically and US-Latin American relations generally.
Having said that, the opposite is potentially true - having 2-3 potential strong leaders in a revolutionary movement that all survive until independence may be a recipe for even more instability...as (generally) has been the historical experience, in Latin America and elsewhere.
The other question has to be asked is if Maceo or Marti wins out; the racial identity question would undoubtedly be an issue - the Cubans had their own internal divisions, obviously even more so in the Nineteenth Century, that were masked by shared opposition to the Spanish among the revolutionaries.
Now, perhaps Maceo and Marti are exemplars and can rise above that, but there are always going to be those who could not...
Interesting question, though.
Best,