I find it funny how random all the TOS Era Phasers look, they have no clear line of progression in design like the TNG Era ones do. You can see a pretty clear progression from the Dust Buster to the Dolphin Phaser in TNG, with TOS they seem to just design something with no regard to previous ones.
The only ones that seem to be similar are the actual TOS Phaser, and the Star Trek 3 one. The TWOK and Assault Phaser share no design similarities to the other 2.