Many claim that Galatians 1 precludes multiple gospels. But it's simply them ignoring context as is too typical of many.

Gal 1:6-9 (AKJV/PCE)
(1:6) I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: (1:7) Which is not another; but there be some that trouble you, and would pervert the gospel of Christ. (1:8) But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. (1:9) As we said before, so say I now again, If any [man] preach any other gospel unto you than that ye have received, let him be accursed.

There is a specific audience involved here. Once you take that into account, there is no problem at all.