allow your opponent to easy grappling access

[güey]

Would you tell me please if "allow (somebody) to (something)" is proper English?

Keeping both arms tucked would simply allow your opponent to easy grappling access to your main trunk.

 

[Tarheel]

I would omit the first "to" there.

 

[5jj]

Would you tell me please if "allow (somebody) to (something)" is proper English?

No, you can allow somebody to do (verb) something.