This can be done. If you limit each DHCP Server to certain ranges. See comments from @Bucking_Horn on this subject.
As a general advice, you could run two DHCP servers on the same link, as long as their IP address pools for dynamically allocated IPs do not overlap, and you should make sure that your static IP address allocations (aka DHCP lease reservations) would be identical and outside of both your DHCP server's IP address pool ranges.
You should also note that only the DHCP server handing out the current DHCP lease would be aware of a client's hostname as presented by the client during DHCP lease negotiation.