BUR #17692 has been approved by @nonamethanks.
create alias sig_sauer_p220 -> sig_p220/p226
create alias sig_sauer_p225 -> sig_p220/p226
create alias sig_sauer_p226 -> sig_p220/p226
create alias sig_sauer_p228 -> sig_p228/p229
create alias sig_sauer_p229 -> sig_p228/p229
IMFDb says
The P226 is basically the exact same weapon as the P220, but adapted to use double stack magazines...
1.) There are no visually distinct differences between each handgun models. Both P220 and P226 bear the same external appearance and mechanism as well. You can see this image for reference. Notice the slide contour, trigger (guard) shape, and hammer. Nothing is substantially different externally despite custom wooden grip panels compatible for both variants, and newer models may have rails under the dust cover. . P225 is just shorter P220.
2.) For the same reason any Heckler & Koch-designed weapon name tags bear the H&K prefix for standardization and searchability while making them shorter.
3.) Nuking those tags manually by a single user (even in favour of more general model names) is a generally discouraged. While this BUR seeks to maintain tagging gun models accurate without causing tag count bloat.
4.) Both SIG Sauer P228 and P229 are basically shorter P226. P229 just have heavier slide. The size difference is still noticeable, especially if context and more details are available. Furthermore, both have rounder trigger guards and rounder profile compared to the parent P226 with squared-off one.
Source
Updated