I expect we'll be linked with every ex Dunfermline player that played under Johnston, Myles Hippolyte being another name on the rumour mill. Moffat is a good player but whether him and Dobbie would be a good pairing is a different matter, we'd need someone to do the running for them.
As for Marshall, rumour is he's pricing himself out of a new contract, unless there's a bit of compromise he will probably be away. He had a late change of heart last season of course so nothing being taken for granted.