ssh, bash perl?
If your seriously using ssh bash and perl alone to manage large numbers of systems, even smallish numbers(more than 50) then you really should look at better tools like cfengine or puppet.
ssh bash and perl alone are far too limited to handle real distributed admin work, unless of course your writing something along the lines of cfengine or puppet in perl ..
Just last week as an example my company built a new edge location in London(I'm in Seattle). We sent one guy out with 1 server running ESX and a VM with enough data to seed the rest of the network. He configured all of the remote management cards, the network guy got the VPN up, and I remotely installed ~55 physical and virtual machines in roughly 6.5 hours over the WAN including all application configuration and everything. And that was using real remote installs, not stupid image-based crap.
It could of been done faster though I decided to throw a wrench into things and revamp my kickstart setup at the same time which made me have to go troubleshoot some things and re-install some systems to fix them.
But all in all it was a pretty good day.
Wouldn't of been possible in that time line to do it without cfengine though(I haven't used puppet hear it's pretty good). My cfengine configuration is about 20,000 lines, to give an idea of the number of variations and tests that the system runs to ensure compliance, and that compliance is re-checked every single hour of the day.
I suppose I consider myself a jack of all trades guy whether it's systems, storage, networking, automation, monitoring, and architecture. It's really rare that I physically touch hardware these days.
I don't personally know anyone else that has my skill sets, though they weren't easy to come across, made a lot of sacrifices over the past decade(well worth it in the long run I believe, no regrets).
Pick the right products and you can scale pretty damn well.