It depends on what kind of splint. There are different kinds, but they can run that high. I would still get at least one more opinion as there is always a risk with a splint as your bite will be altered, doesn't allow for natural shifting of teeth, etc. and you want to be sure this is the best option to try.
I wear a night guard that is put in hot water then cold water to mold. My TMJ rarely gives me issues - only when the guard gets really worn and thin over time. For some people, that is all they need for TMJ and a splint can be overkill - but you really want a couple of opinions.