Many teams lack manpower, but there are several reasons for that. Often, it's a real lack of manpower. In some cases, it can be that the team is unable to accept help offers, but I suppose this is a minority of cases.Judging by history, I don't think our current approach is exactly flourishing. We've mentioned sysadmins, list admins, web admins, all of those had breakages. We haven't mentioned bug admins, ftp admins, docs admins, key admins, account admins, but all of them had fairly major issues too. It's hard for me to recall any other major infrastructure team in Debian where I can point and say that they have always functioned fine, i.e. they only had technical issues (rather than manpower issues).
I share Lucas's concern that the number of teams in the second case may not be worth a GR. I recommend to start by finding at least two teams in this case and trying investigate what happened to these teams.