The following is a list of the League and American Association players who jumped the reserve rule and had the good sense and honor to stand by their written contracts with the Union Clubs: Bradley, with the Cincinnatis; Dunlap, Shaeffer and Jack Gleason, St. Louis; Hugh Daily, Chicago; Buck Weaver, Philadelphia, with a strong probability that Gross will also play with the Chicagos. There are only three deserters, Mullane, Mansell and Corcoran. Mansell regrets his perfidy, and told Bill Harbidge, who met him in Pittsburg the other day, that he was sorry he had not lived up to his contract with Mr. Lucas. This is not a bad record for the Union Association, considering the disreputable fight that has been made to induce players to desert.-[Cincinnati Enquirer.]
-St. Louis Globe-Democrat, April 2, 1884
So the Unions got six guys to jump from the NL and the AA. While the Enquirer didn't think that was a bad record, given the effort that Lucas put into getting players, I don't see how it can be seen as anything other than a failure.