Probably won't beat KC-Bridge, which can simply steal most of the feoda from the masterpiece player, likely forcing them to play big money on a board with KC and Bridge.
Depends on the support of KC-Bridge. If there's no support: good luck colliding 2 KCs and 3 Bridges.
About the combo Feodum/Masterpiece, how do you play it? I haven't played a game featuring that combo yet, so please mention the basics. How do you open? When do you buy silver, when feodum, when masterpiece? How do these things change if your opponent mirrors or does not mirror?
I think you open Silver/Support, where support is either +Buy or terminal draw; if no good support is available at 3/4, Silver/Silver--you're going to flood your deck with Silver anyway. I would probably also open MP on $5, and MP on $5 is probably an OK buy during the second shuffle as well.
In a non-mirror I think you want to Silver-flood early, especially if there is +Buy available, but probably go after Feodum with $4 or $5 after the second T4. The mirror feels like it will be tricky: If you win the Feodum split 6/2 but your opponent wins the Silver split 30/10, your opponent has more points from Feodums
and is going to be able to buy Provinces more readily! I think winning the Silver split may actually be more important. Breakpoints:
Feodum 4/4 goes to whoever gets the 21st Silver
Feodum 5/3 requires the split winner to get 15 Silvers
Fedoum 6/2 requires the split winner to get 11 Silvers
Feodum 7/1 requires the split winner to get 6 Silvers
But the thing is, flooding with Silver makes it easier to get Silver even faster. So I'm not certain here...