V.K
Starting XI
Yes, single ID, single model, both specificstadium and tournamentdressing additional files.As I understand right you want to have one model for all the tournaments and with different tournament dressing textures in the tournament folder? I'm not sure what you mean by "creating new stadium". You want to use the specificstadium function?
As an example, St Petersburg stadium WC 2018 with custom WC 2018 dressing is specificstadium_xxx_2018_textures.rx3, switch the custom dressing to Euro 2020 graphics and now we have specificstadium_xxx_2020_textures.rx3, add a tournamentdressing file for Zenit and launch a Zenit game - now the tournamentdressing overrides everything and it's a Zenit version.
The base version (stadium_xxx_textures.rx3) is the WC 2018 version just with custom dresisng turned to grey walls and active tournamentdressing feature so that absolutely any game can be played there with new graphics.