I dont think Reservists are a Problem... As Long as they don't Play for 2 Regiments participating At RGL and aren't Invites it Is no Problem because at all they Are more or less retired Players (as I define Reservists) or players Who don't attend very often, but I don't See a Problem if they only Play for one Regiment in the RGL.
As this seems to be an issue the captains are complaining about, I had an Idea I've already told Rommel about, making some Lists for every Regiment participating. Where they give the names of the Players that Will probably Play the Whole Season (This System Is running for example at NWGFL, there even with the ID's). Changes (Leaving People new People etc) would be told to the organisers or Whoever Is in Charge of this. Would make it kinna easier for all, especially the referees, to avoid Invites. The Number of Players on this List could be limited to 25 or 30. Just an Idea. Wouldnt be that intense to Manage.