[quote=@Vilageidiotx]
So long as you don't do anything weird with them, go for it.
[/quote]

Nop, nothing that strays from official timeline. Most Ghassanids never converted (to this day in fact) and remained Christian. While some did join the Muslims (either converting or keeping their religion), the majority remained loyal to Byzantium until the Battle of Yarmouk, which was when they decided to throw their lot in with the emerging Arab Empire.