Ok, then suggest you to setup you environment as follows:
1. Replication of all 4 VMs from Hyper-V1 to Hyper-V2, on-host proxies.
2. Use Veeam server as a backup repository.
3. Configure backup job to start during night hours, backups should go to Veeam server repo.
4. Configure backup copy job to start in 5 minutes after backup job starts. Backup copies should go to an offsite Hyper-V repository.
5. Configure WAN accelerators on both Veeam server and offsite Hyper-V.
In case of a Live system disaster you just fire up your replicas on the second Hyper-V instantly. In case of Smoking Hole In The Ground event you run instant recovery on your offsite Hyper-V or, optionally, you might want to create another set of replicas from your backup copies
on that offsite Hyper-V. Also don't forget to have a backup of veeam server configs on all three sites.