Actually by cannon, one in every 10,000 people has the Gift. That roughly 1:~40,000 ratio ignores the mundane populations of Novorod, Levant, and half of Thebes. If you include those areas, the ratios get even more out of whack.
While the Order does not control the mundane aspects of the land they inhabit, they very much control it in relation to magic and other magic users. They need enough Magi to protect and police that area against outside groups. Considering the low ratio of combat Magi verses all the types worthless for this and how slow the Order is to respond to things, the Order would have a difficult time protecting themselves from a concentrated attack by another group.
Additionally all the little sub-groups within the Houses and all the Mystery Cults are limited to no more than a handful of members possible. While interesting flavor wise, in any given game most of them can not exist due to lack of sufficient Magi. Unless of course all the Magi in your game are members of multiple "special snowflake" groups each.
I am bringing this all up because if you are going to go through all the trouble of tearing down and rebuilding all the Tribunals, then you might as well go through the trouble of changing the ratio of Gifted:Mundane and the total membership of the Order. That way you actually have enough bodies to fill the increased number of Tribunal and all those little "special" groups. It would also make a Tribunal in Ireland and Scotland much more capable of supporting an actual population of Magi without almost all of them being transplants.