VPNs Subnets Workgroups NetBIOS traffic, implications XP Pro, Vista

I just connected 3 sites with VPNs between each pair of them.
I'm trying to get My Network Places to either show or not show the computers
at the other sites. At times I can see all the computers and at other times
not.
I can enable/disable NetBIOS broadcase traffic over the VPNs. This has an
effect but I'm not sure what all....

At one point when we had this set up earlier it seemed that the Master
Browser for one site was located at another site. I'm sure that the NetBIOS
broadcast traffic was enabled in the VPNs.

There is no WINS running - this is strictly peer to peer networking. It has
served us very well and keeps things simple.

The subnets are subnets of 192.168.1.0 255.255.255.0
192.168.1.128 255.255.255.224 with workgroup of WORKGROUP
192.168.1.160 255.255.255.224 with workgroup of WORKGROUP
192.168.1.192 255.255.255.192 with workgroup of WORKGROUP

We have turned off the computer browser service on most computers in an
attempt to speed things up and to make them more deterministic. Even so,
this means that there are perhaps 2 computers per site that have Computer
Browser service started.

What I need is a simple system that will allow access to computers from site
to site - drive mapping perhaps or at least visibility into shared folders;
access to printers; etc.

I could turn off NetBIOS broadcast traffic altogether. What would that
mean? What does having it enabled do? It appears that having it disabled
allows each site's computers to be seen reliably in My Network Places on
computers at that site / subnet.

I could change the name of the workgroups so they are unique to each subnet.
Might that be a good idea? What are the implications? Moving laptops from
one to another would be a bit more trouble?

I'm OK with accessing computers by their IP addresses and folder share names
only. Whatever .... the My Network Places should be consistent at each site
and reliable.

I'm looking for suggestions as to how to configure things while keeping a
peer-to-peer network without WINS, etc. and suggestions as to what to expect
with this or that set of settings or possibilities as above.

Turn off NetBIOS via the VPNs - Use a common workgroup name.
Turn on NetBIOS via the VPNs - Use a common workgroup name. ... I have it
this way now
Turn off NetBIOS via the VPNs - Use a set of unique workgroup names.
Turn on NetBIOS via the VPNs - Use a set of unique workgroup names.

I have added persistent routes to *some* of the computers so far so that
they point to the VPN when trying to access the other subnets. This is not
the case on all computers ..yet.

With NetBIOS broadcast traffic enabled on the VPNs, I'm not seeing ANY
computers in the My Network Places or Workgroup but it's only been 45
minutes or so.....

Thanks,

Fred