Very funny to see so many different opinions and feelings towards this news!
Thank you Cagemember 321, for your interesting take on the matter. I can totally see where you're coming from. And I agree a lot with what you've just said, but I think I have a different conclusion.
The first singer, John Carson's voice sounded a lot like Fish indeed. Great singer! Arena was only a project back then and it was never the intention to make it a band. I think Carson didn't want to commit himself. John's voice was very melodic and kind of theatrical, but not so much. The music was very Neo-Prog in an early Marillion/Pendragon sense. I think "Songs From The Lion's Cage" is a wonderful album, but I'm glad that Arena took a risk and in the end evolved into something darker and original.
Paul Wrightson's voice sounded kinda like John's, but when you compare it to Fish, they don't sound much alike to be honest. Only on a superficial level if you'd ask me. Especially on "The Visitor" Paul's voice was very much his own. I think his voice was perfect for Arena. Very theatrical, very emotional. Paul W is the perfect balance between Rob Sowden and Paul M (who both have their own unique abilities in the extreme), while still hinting back to the John Carson days.
Rob Sowden, again, has some hints of previous Arena vocalists, but only in the way he's singing, not the 'colour' of his voice, if you get what I mean. Rob doesn't sound like Fish at all! Again, his voice suits the music perfectly. There's so much drama in his voice. The feeling of despair. I like that very much! On "Contagion" (probably the best Arena album? At least top 3!) he does such a wonderful job! Although objectively he's maybe the lesser of the singers, he's on two of my favourite Arena albums and I rate those albums really really high!
Paul Manzi doesn't sound like any previous Arena singers and with him, truly, a new era started. The funny thing is, Paul Manzi is the best singer Arena have had and he can do anything with his voice. The guys gave him a starring role in the band and rightly so. His voice is very versatile. He can do high, he can do low and everything in between. With him, they got an A+ singer. For the first time in my life, people around me didn't complain about the music I was listening to. But with him, Arena had to give in a little bit on one thing: the emotion, the feeling of despair and fear. That was a trait that was so perfectly done by Paul W and especially Rob.
It's interesting to see where Damian Wilson will fit in all of this. I'm sure Clive Nolan and the others will know what to do and write music that is (again) perfectly suited for the singer. Damian is no minor in the field. I really like his voice. I agree with Cagemember 321 that this will probably make Arena less dark. Damian will not be able to sing as low as Manzi. But other than that, they are pretty much alike: great singers who will not be caught singing a false note, (objectively the best, so to speak).
In a way, with Damian, we're going back to John Carson days.
In the end, I can't imagine the Arena albums being sung by a different singer as it is. Again, every singer is perfect for the respective albums.