There is not really a "VRS compliant" concept when it comes to injecting data into VRS.
The matches have to be HLTV covered and marked as "ranked" and then they will just be injected.
HLTV controls what id's the players and teams will have and we have to assume that the players will use their normal nick and id in this event.
The first big question is if a team lends out 3 players to a national team, will they then be registered under a National teams id and name on HLTV or will they enter the event under their real teams name?
No big team will allow 3 players and 2 randoms to play for their org in this event as it will effectively be 2 rosterchanges in VRS which will have real implications on the upcoming ranking. The team could get in trouble in future events where invites are based on that ranking or they could lose ranking due to older matches no longer being eligible for the team due to the 2 new players taking 2 regular players place.
Example:
If Aurora sent soulfly, XANTARES, woxic to play this event right now, they would lose all the points from the matches from before soulfly joined on the next VRS rank and in the future events based on that list they would be locked to have those 3 players available, so no room for substitutes in case of sickness.
Thats just some examples of the total mess and integrity issues this could and would give.
If the 3 players from a team were playing for a national team with its own id on HLTV in this event, then their real team would lose all the points belonging to these 3 players.. and when they then play again themselves later, then they would "steal" the points from the National team.
So yeah, you can inject all sorts of data into VRS but the outcome will be a ranking potentially totally messed up.