I favour using the STF route now, simply because of the options it allows. To make it work you could do the following
1) Instead of Class Restrictions within a round go for class restriction within a squad. Each team is being asked to register 16 players so make them register no more than 4 ranged and 4 Cav. Within an actual round they can use which ever players they want.
2) When a team Registers they must assign each of their players a squad number and that player must then create a STF Char using that squad number. For instance if I was registered with squad number 9 I would have to use the STF name of UK_Tomas_9 and I would be registered as ranged
3) Each team then gets to design its own banner which will be put in a special Nations Cup Banner Pack
4) Within the tournament all players must use one of the Heraldic Armours (but not transitional). Archers are the only exception and they can simply choose something that matches as best as possible
5) Before each match, the referees can quickly check that each STF Char has the correct name as registered and that they are the correct class. A quick glance will ensure that the armour is all correct.
6) Finally, to ensure that all chars are in fact STF I am hoping the Meow will do us a favour and validate all the chars at the start and then at the end. I am assuming that a simple query on the database will be able to bring up all players with the UK_ tag and that you can see if they are STF and when they were created. If so then this validation should be extremely easy.
The system above prevents looms, keeps armour at a level where unloomed bows will still be viable, is easy to enforce and still allows plenty of tactics within a team.
Edit: I'm still not against mains though - i'm just pointing out options
