Workgroups have Limitations

When your network is growing, please be aware about some limitations in the size of Workgroups, as listed in the "Windows95 Resource Kit:"

If your Workgroup grow beyond this limit of 15 systems, you get multiple "Browse-Master". It is better to limit the size of each workgroup to be smaller than 15 systems, you are still able to connect/map drives on systems in other workgroups.

My experience with such "advise" from Microsoft:
Follow it (otherwise Microsoft would not have listed it) !

Also, I have seen a note, that systems on different Network-Segments cannot be part of the same workgroup:
When systems are connected via repeaters and/or hubs, they are still on the same segment, because repeaters/hubs are just acting as signal-amplifiers.

But if the systems are connected to a Server with MULTIPLE network-boards, then the cables on the different network-cards are on different segments, and it is now the responsibility of the server to "route" network-traffic between these segments, which seems to be the reason for the workgroup-limitation, and you need to use LMHOSTS to be able to access such systems.