I'm pretty sure this would work; we have done similar things at work:

              host oddbox {
                        hardware ethernet C8:3A:35:DC:54:59;
                        fixed-address 192.168.1.12;
                        option host-name "oddbox";
                }
              host oddbox2 {
                        hardware ethernet 00:24:21:9A:6F:6C;
                        fixed-address 192.168.1.12;
                        option host-name "oddbox";
                }

Two separate entries with different MACs and same fixed IP.

--Greg