There won't be any.
Very few girls will want to join the Infantry, fewer will pass the training. Almost none will serve any useful purpose in roles that they couldn't already have done.
You will just be opening the doors to leaving the MoD exposed to multiple millions of pounds worth of compensation claims for indirect discrimination and negligence issues. The reasoning will go that female bodies are not capable of the same physical exertions - to make equal physical standards is discriminatory and negligent.
The Army will have the choice between being sexist, or being discriminatory and negligent. Great choice.