Lending Mercenaries different weapons?

[Kurgan]

And if we want another comparison, here is where it gets a little interesting... these are rules for Animal Companion "allies" which may not necessarily apply to other types of mercenaries, but is nevertheless useful for thinking about what they might be able to do, and this comes from the official supplement to Frozen Horror, "Into the Northlands" again from the modern remake line from Avalon Hill. Note that it's under "playtesting."

I also checked the official companion app (v.1.72) to see if there are any other hints but there's nothing in there that isn't already in the above documents that I could see.

[Kurgan]

And finally, for comparison, the first appearance of Mercenaries officially in HeroQuest, from Wizards of Morcar (under the EU rules of course, 1991) gives a very different picture. Of course there are no death saves in the EU rules and these mercs have only 1 BP so their inability to use healing potions (for example, from the treasure deck) makes some sense and it doesn't say you can't buff them with Spells.