You'll need to review the hardware requirements in that Wiki article... as far as recommended number of cores (min 2), memory (min 8 GB), etc... but also the OS requirements.
BIM Server does not have to run on a 'server' - is is an ordinary program and uses your ordinary file system - whether Windows or Mac.
The Wiki notes that it is not recommended to run the BIM Server on a mail server machine - but that really depends on the volume of activity you get on that machine IMHO. But, the ftp or file server could have similar complications. It all depends on how many total users you have and what the load on each of those existing Mac Pro's is ... and how current they are.
Folks will need much more data to advise you. How many total workstations are connected to your network?
What are the specs of each of your Mac Pro 'server' machines? Number of cores/speed, total memory/bus speed, disks - speed and available space, RAID or not?, network speed (assume wired gigabit ethernet?), etc
Having your users make the learning leap from 10/11/12 to 16/17 is HUGE. Learning TW2 at the same time is even bigger. Hopefully this is your plan, but if not, I highly recommend migrating a few users/projects at a time...
One of the forum moderators
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB