yeah, I was thinking the same thing while watching Kuuga myself but I've come to a theory on it. now if my theory isn't accurate, anyone just tell me what they think.
basically, the kuuga belt is a grongi belt by the linto with grongi "technology" or whichever way you want to put it as, I'm going to call it technology just for the heck of it anyway. I think the grongi are born with their belts yet the kuuga belt is given, so hence it can and has been modified, it can evolve which it does to, so hence the more dire the situation, the higher the evolution and the closer it will become to daguba, which is the highest grongi. now I think the linto knew that the kuuga belt was basically a double-edged sword, they can defeat the grongi with it yet it could easily turn the person into what they were fighting against, which would be why they used a grongi symbol for the kuuga warrior, also since the highest the kuuga belt could be would be daguba in their opinions, they used the word daguba uses to describe him, yet without the extra horns, to symbolize he is still their warrior, the lintos warrior. the case of daguba and kuuga looking similar might be because they are at the pinnacle of grongi power, meaning that they are in a beast form without the beast, surpassing all others.
well, that's my theory atleast. not perfect but hey, I gace it a shot! I still think they didn't wrap up the show all that well. I love the show but they didn't wrap up all the loose ends all that well. does anyone know if that prologue for episode...47 I believe, was going to be an episode or not?