While the songs sound pretty darn close, I'm not saying the Florida Georgia Line boys ripped off the Kane Brown track. Actually, I think this is kinda like what happens on the NBC TV show Songland. Have you ever seen it? A songwriter comes in and sings an awesome version of their song. Fast forward through some retooling and VOILA! It's a brand new song! That's how I see this situation.
BTW...Kane Brown and a couple of his co-writers of "Short Skirt Weather" are also listed as writers for "I Love My Country."
Here's the mashup!