I always assumed that the dovetail pattern was designed as a more secure way to make half-pie looking chips when an inlay was placed in the center.

And the bow-tie chips you show will look like quarter-pie chips when a center inlay is placed on top.

Of course, these patterns have be used "naked" with hot-stamps, too. As evidenced by those neat dovetails from years past.

And to further muddy the waters, there are "true" half-pie chips in existence also, such as the various Tropicana 2-color "Match Play 5 NCV" chips.