Wise also to replace a fall guy (6)
I believe the answer is:
stooge
'a fall guy' is the definition.
(both can mean someone who takes blame)
'wise also to replace' is the wordplay.
I cannot quite understand how this works, but
'also' could be 'too' (synonyms) and 'too' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stooge that I've seen before include "Comedian's sidekick" , "Comedian's foil" , "Performer who is butt of another's jokes" , "A comedian's assistant, butt of his jokes" , "Yes-man" .)