Just my 2 cents on the matter of group formation, not that it particularly matters since I will be gone once this starts.
Change the groups drastically. I would go with the Champions League system (Soccer/Football). In Champions League you have 4 pots. Pot#1 is for the teams that are the best (Real Madrid, Bayern Munich, Barcelona and so on), Pot#2 for those slightly weaker (Dortmund and so on). So the Pots basically are a way of ranking. The ranking is done by looking at recent performances in the most recent years of Champions League. Then 1 team from each pot is drawn for each group, so each group has a team from Pot#1, #2, #3 and #4. Each team then plays every opponent twice. The two teams coming in 1st and 2nd qualify for the next round, the 3rd placed is moved into the Europa League (same as Champions League just with slightly worse teams) and the 4th placed is completely knocked out.
Transferring this onto NW would be almost exactly the same, but since this is the first season of TNWL you should rank regiments based on their performances in NANWL or in general in 1v1s. Why go through all this trouble? Making skill-balanced group stages might be fair for all regiments, but group stages are not supposed to be highly competitive or the most important phase of a tournament. If you put 63e, 71st, 58e and 18th in one group for instance you will basically have 2 possible title contenders knocked out straight off the bat. Not to mention those qualifiying from this group would then face regiments from weaker groups and destroy them in the knock-out stages. The knock-out stages should be highly competitive and I'd suggest having 2 legs here as well. To allow weaker regiments to continue playing even after the knock-out stages just have the 3rd and 4th in the groups play in their own knock-out brackets.
Anyways, sorry if this was a bit hard to read, wrote it quickly. Good luck with this!