One of the founding members that started Polaris split off and started the company that would become Arctic Cat. As stated Textron owned Polaris much earlier and sold it. No overlap between Polaris and Arctic Cat on an engineering or manufacturing level. There are some companies that have supplied parts to both, TEAM clutches and Hayes brakes for example, but nothing is really the same design other than the Hayes master cylinders and secondary clutches for a few years.
Much of the Cat history can be read here:
https://www.bosscatlegacy.com/acproto/acprotohis.htm
An old Hot rodder like yourself would probably enjoy checking out some of the old Boss Cat race iron too!
https://www.bosscatlegacy.com/sitemap/sitemap.htm
The parent company that now owns Polaris also owns Klim, Timbersled, Ice Age, and probably some others. Arctic Cat bought Motorfist before the Textron buyout, and they've done a good job of trying to run that into the ground too.