At the moment, I only know one way to determine which Emacs functions are called by any given Evil command (e.g. a sequence of key bindings in the Normal state): read the Evil source code.
Is there a more reliable and efficient way, and if so, what is it? For example, does Evil (or Emacs) have a mechanism that allows the user to tell Emacs:
"When I enter my next command, show me afterwards which Emacs functions it mapped to."