Skil got purchased by Bosch decades ago.
Bosch folded Skil into its US S&B Power Tool division ( technically another owner was involved, but Bosch bought them out).
S&B Tools stood for Skil and Bosch.
Bosch at that point manufactured a lot of tools in the USA.
The Bosch tools were the fancy tools, sometimes made in the USA, and sometimes Europe( usually Germany or Switzerland), with innovative features similar to the kind of thing Festool is now known for.
The Skil brand was mostly used for the simpler lower featured “industrial” tools, like worm drive saws, and basic biscuit joiners etc.
Eventually bosch started taking there European homeowner or hobby tools, and started selling those under the Skil brand in the US, with a few sold under the Bosch brand.
Then Bosch started making and importing cheap homeowners grade tools from Asia and sold these tools under the Skil brand, with the quality Skil holdouts being the worm drive saws.
Eventually, around the time Amazon started selling tools, Bosch started importing tools made all over the world, and sold the tools under the Bosch brand as well as the Skil brand.
Bosch’s reputation took a nose dive in the US around this time, and Festool wound up as the “high wuality” tool brand for woodworkers, even though the Bosch tools were sometimes better though out, and were previously occupying the same market segment, but with Bosch considerably cheaper than typical Festool prices.
I presume Chervon must have been manufacturing a bunch of the Bosch designs, particularly the worm drive saws under the Skil brand, after production got switched to Asia, and so Bosch sold Chervon the Skil trademarks etc, even though some of the Bosch and Skil tools currently have similar basic designs, and may still be made in the same facilities.
Bosch currently seems to be trying to regain there higher market reputation.
Skil and Skilsaw are producing more innovative designs than what was released when they were the middle range Bosch brand.