Probably a waste of time at this juncture. You're a patent examiner, so you probably already know, but the endgame of most legal actions is not to win the case in court, but settle or just exhaust the opponent. You need to be prepared to spend (waste) a lot of resources to do that on the offensive, and as you say you (and 'they') don't have them. "Mutually Assured Destruction" (mad, haha)
Rather, I would suggest spending your resources on getting market/mind share as quickly as possible. You already know your competition, so fight them on merits. Sometimes 'merits' is 'doing the right thing' (i.e. complying with regulatory requirements).
So if you want to wage war on this ground, you could instead make a marketing initiative emphasizing your compliance with regulation XXX. E.g. "naturally we comply with, and exceed, ISO-xxx, as you should ask any of your vendors to do as well".
Think creatively, and play nice. Your enemies sometimes become your allies.
E.g. oldie but goodie: SEA vs PKWare. Legal actions are so 1750 bc; too bad we really haven't come up with much better since, alas...