Removing OSPF and using Auto Last Hop

We are in need of removing OSPF from our Viprion’s. Initially prior to me joining my company as the F5 engineer new viprion 2400’s were setup with the virtual servers all using a 10.210.10.x or 10.210.11x. The VLANS and their associated subnets were predefined in the checkpoint firewalls (virtual FW instances) for hosts on those subnets. The firewall instances are mapped to the vCMP guest to service those specific vlan’s. The self-ip’s are defined on those subnets with .4 (floating), .5 (active), and .6 (stand-by). Initially using auto last hop we found that all VIP’s from each vCMP guest were ARPing on all firewall instances which caused issues. I configured OSPF to alleviate the ARP issue, but anytime the FW’s have a problem LTM traffic is impacted due to the LTM’s acting a DR and BDR. I am in need of advice for removing OSPF and going back to auto last hop, but I need to understand the best route to take; such as changing the subnets for the virtual servers on each vCMP guest to be unique. So would it be possible to configure the first 3 octets of the vip’s for (say) guest 1 the same, changing the first 3 octets with each consecutive guest? The idea is to use this same scheme on the check point virtual instance associated with that guest. We don’t own the address space for the hosts and it would not be possible to configure the vips to be on the same subnet as the hosts. Any advice would be helpful.

Thanks