Ideally Ben is getting 20-25 effective minutes per game off the bench at this point in his career playing behind a solid veteran. We haven't been able to make that happen yet though. Belinelli is a shooting specialist who's best used in a bench role so signing him pretty much means that Ben has to be the starter. Or we could dick around with various combinations of Belinelli, McLemore, Anderson, Collison and Curry in and out of the rotation so that nobody knows what their role is and everyone is unhappy.
Curry and Anderson are just "deep roster fillers", or should have been contemplating them that way as roster orchestration was being established. We desperately needed bench scoring and scoring range depth so Marco was a logical choice.
Ben is cheap, fantastic athlete, costs you nothing as far as acquiring because he's all ready yours.
It's not a great situation, but a make do.
If Ben performs, you've got it cheap next year too. If not, you've got the option to trade/invest differently in the off season.
Looks to me like a decent tread water scenario, as the "fix" was likely not attainable.
I'm not sure Vlade anticipated using Marco like Korver either.
Don't feel handcuffed either as I think if you wanted to move either one of them, someone would take them.
But to gamble on Matthews was too risky though if you ask me, that's a lot of coin, a lot of risk. So I'm in agreement with you on it not being a good call.