Welcome back Anya. Hope everything else is going well with you guys and hope this thing will make progress this year.
If your PD is retrogressed, I think there is really no point filing a WOM because they don't have any duty to process your case in retrogression. But if it's current, you don't necessarily have to use an attorney to sue them. It would be pain in the arse and take a lot of time, but you could file it yourself. I remember there is a very detailed post about how to in this forum. You can search, but I'll post it if I can locate it.
Is the husband's security check cleared yet? Ombudsman takes a month or two before writing back to you. If his NC is still pending, though, all they say is they cannot do anything about it.
As for visa number assignment prior to retrogression, yes, that's my understanding. That was how all those approvals during the months of August/September occurred. I cannot come up with any good idea how to know if it is assigned yet or not other than keep calling. Or infopass. Still information you get may not be accurate. My spouse called and the rep said it was not assigned yet, and she got an approval email the same day. So go figure. Our senator got some information for us twice. Not sure if the information was right or not, but at least they attempted to help us.
Hang in there and keep us posted.