Can lpd communicate to two remote printers if they don't use the same
TCP port number?

I don't think so and I'm hacking mine to do this by using a new
capname "pt" for remote port by name (defaults to "printer".)  You
have to edit /etc/services to add "altprinter" or whatever.

Do you think that this should be "standard issue" or should I keep
this hack to myself?

Yes, some idiot here configured one of the printers to use port 2000.
No, I don't have the authority to fix it (or the time to run around to
umpteen PCs to change them all.)

~Ken