Might be moot. If Gau still has Rage as a command, it'll overwrite his weapon animation each time he uses it each battle, changing it to whatever weapon the monster attack is set to look like.
...Which is honestly cool because you can set enemy attacks to a bunch of random weapons and Gau will pull them out of hammer space, but it will pose a problem if you're setting up your pummel animation by weapon ID.
Everything's approach is probably best; give Gau a new command that is titled 'Fight' but works like Shock, triggering a custom spell/move with an animation of your choice. There might be trouble with damage scaling, though, if you call a spell that isn't the 'battle' spell. You'll also have to include said new command as an exception in the Magitek and Fanatics Tower command overrides, starting at C2/532C [though the special case skips you want to add to start at C2/535E].
...Though...
You're probably low on available commands, so perhaps a subroutine special case for Gau in the existing fight command is called for. It'd be similar to Umaro's, except instead of a variable branch you'd run one subroutine for Gau that functions similarly to Storm, but with damage calculated from his weapons like Charge.
...Which is honestly cool because you can set enemy attacks to a bunch of random weapons and Gau will pull them out of hammer space, but it will pose a problem if you're setting up your pummel animation by weapon ID.
Everything's approach is probably best; give Gau a new command that is titled 'Fight' but works like Shock, triggering a custom spell/move with an animation of your choice. There might be trouble with damage scaling, though, if you call a spell that isn't the 'battle' spell. You'll also have to include said new command as an exception in the Magitek and Fanatics Tower command overrides, starting at C2/532C [though the special case skips you want to add to start at C2/535E].
...Though...
You're probably low on available commands, so perhaps a subroutine special case for Gau in the existing fight command is called for. It'd be similar to Umaro's, except instead of a variable branch you'd run one subroutine for Gau that functions similarly to Storm, but with damage calculated from his weapons like Charge.