Zsh, 5851 bytes
b=$g()<<<${(j::)${(os::)21:l}// }
<<<${${(j::g $1)/${(os::)1:l}//g }/$b$2)}
Similar to my other anagram solution, again using Zsh's gnarly parameter expansion. Added a few bits to lowercase everything and parse out spaces. Tried to jam everything into one fancy expression but Zsh kept complaining, so I separated out $b
to make it work.