Definitely installing a dedicated DHCP server would be preferrable.
However, you could split the scopes by excluding half on each controller. e.g.
Controller 1:
Network - 192.168.1.0/24
Excludes - 192.168.1.128 - 192.168.1.254
Controller 2:
Network - 192.168.1.0/24
Excludes - 192.168.1.1 - 192.168.1.127
This will stop the controllers issuing duplicate IP addresses.
David