Hmmm, I think that arousal fluid is exactly like ewcm, but it's my understanding that the other fluid is watery, like pee, and can be mistaken for it often.
I think we are getting confused between arousal mucous (which is like ewcm) and female ejaculatory fluid (which is more like pee).

My experience of ewcm versus arousal mucous is that ewcm is "stronger" and can be stretched more.