DD's Brownie pack was great - they were really active and had loads of fun. DD made a lot of new friends there and had a great time. They did pack holidays to PGL and made/raced rafts, did hire wire ropes, etc. On normal pack days they did archery, bowling, bouldering and climbing, orienteering, camp fire cooking, swimming, etc. They did various crafts, raised money for charities of their own making, put inn shows, took part in challenges such as learning to use the equipment for key hole surgery, had talkers in to take about future careers, etc.
Mine in the 70s was mainly based on the Brownie hut but I remember having fun.
Yes - they wear a uniform - but then so do many groups; it is to have their sense of belonging and working together as a team. Many groups have uniforms - gymnastic groups, dance groups, drama, etc and obviously schools often too.
The toadstool thing is to do with the Brownie story - which takes place in a woods iirr.