|I am sorry to say this but your server team doesn't understand Disaster Recovery nor do they seem to be aware of the different levels of disaster recovery.|
You will find that when you try a true failover the workstations on the production domain won't be able to talk to the DR servers since you have separate AD and workstation trusts/sids/guids
Here are some basic examples of DR
Level I DR
multiple DC's with GC/DNS [this is a standard MS recommendation stated in all training courses and ms documentation] and dhcp ready to authorize if dhcp server goes down
raided disk subsystems
backups tested and stored off site with rotation scheme
Level II DR
All of the above with an additional large wan pipe to an offsite server room that is accessable to workstations with the flip of a switch. All servers in same Forest/domain with server to server communication /DFS/FRS between them
Level III DR
Image servers taking snapshots of your servers which is then xferred off site to the DR site image server. Same existing hardware at each site and either image per schedule the DR site servers or be prepared to image and flip the switch.
Many permutations are possible depending on what is considered an acceptable time lag for DR.
If you haven't taken care of the level one basics you have no DR possible.
Server based application failover is the largest consideration and the toughest to implement