Sudo doesn't work that way (unless you've configured it wrongly).
When you specify a command in the sudoers file (via visudo), you specify the full path to it. If a user renames a shell to be the same as an existing command in their sudo command set, the path will still be wrong so it won't work.

If you use wildcards in the sudo config, you need to be careful that you don't allow the execution of user created binaries. Do this by only allowing wildcards within filesystems the users have only read access to. In general, keep wildcards to a minimum as they open a lot of hard to forsee options to your users.