He is a talented guy, good voice too. The roles require strong comedy skills which isn't something a musical theatre actor is going to be able to pull off.
Plus the show doesn't have a strong history in the uk so it's going to need all the help it can get to bring people in
Of course some can, but The Producers requires a high level of comic timing and comics are obviously a natural choice. I struggle to think of any naturally comic musical theatre actors over here. It's not just about 'being funny', there is an art to it. How many times have you seen funny lines being just thrown away because the actor hasn't landed it right. Wicked and Hairspray are two shows off the top of my head where I've seen the funny moments now land with an audience because of the delivery on stage
Princeton is right, names sell and The Producers whilst doing ok here was never a runaway hit. When the UK tour launched with Peter Kay in Manchester for 3 months it was sold out every night, when he left the show after the Manchester run it pretty much collapsed (so much so they called Kay back in to do a few weeks)
Namo i love u but we get it already....you don't like Madonna
Everyone does Nathan Lane in this role. Its what the writer wanted. Henry Goodman tried something different and look how that worked out. Max is the the one role I think needs someone who understands the very specific humour that role requires and unless Manford spent his youth watching Zero Mostel I doubt he has it. Quintessentially New York.
Sounds good, I liked the tour (saw it with and without Peter Kay) and think Jason Manford would be good, there is a clip on Youtube of him singing Stars from Les Mis.
I agree with your original point, but to add to it, that it to sell tickets we have to stunt cast the roles, instead of employing theatre people who can do musical comedy well such as and a poor example Douglas Hodge as Max and someone like Stephen Ashfield as Leo.