As a Cap 14 team captain, I've seen such mis-matches first-hand. However, two of our best games this season have been against the ex-Karori Cap 9 side and Tawa AC United #2 (1-4 and 1-3 losses). Being able to match these teams for a lot of the game and not coming off with a coronary is actually a point for us to celebrate. Personally I like the mid-season promotion-relegation as it means that if there is a gun side in the grade, at least we only have to play them once.
For this year, the Goldenrods were actually supposed to play in Cap 13 and the Uni Wanderers in Cap 14. We decided to swap as we felt the younger guys (who'd beaten us on the last match of last season) deserved to play higher than us. As it turned out with team defections, the Wanderers ended up in Cap 12.
I agree with Feverish that it should be a club decision to sort out. Some tough decisions are required, especially if you get a new team that is much better than some of your established sides - effectively you may have to ask that established side to drop down a division or two to let the new side take their spot.
As a former club captain I remember pouring over the list of grade allocations we received at the start of the season and the committee discussing whether we should make any changes. In a couple of instances we swapped teams around in adjacent grades. One of our big issues was knowing how well some of the first-year student sides were going to play in comparison with old-hands. Trials helped us a little.
Perhaps clubs should be having more of an organised pre-season for their social football teams, if only to judge how they compare to each other.
UniGoldenrods - Propping up Capital Football since 1994