As far as I know the halberd was the main weapon (supplemented by the pike) until after the Battle of Arbedo in 1422 when it became the other way around but I've been curious about the average ratio of pikemen to halberdiers (both before and after the pike became the main weapon). Does anyone have some information about this?

I realize there probably wasn't any fixed ratio as such but I can't imagine they just lumped them together at random proportions since they did fill different roles.

I have heard the same regarding Arbedo being the turning point towards more pikes and less halberds, but nothing changes overnight and as you say there must be a lot of variance before and after. I suspect there are quite accurate numbers out there from cantonal records and such, if you can find them...

Osprey has some numbers in "The Swiss at War", for example a Zurich contingent in 1443 was about 58% "halberds and axes", 23% pikes, and the rest with crossbows and a few guns. So still plenty of halberds even 20 years after Arbedo.

At least some Swiss armies included significant numbers of halberdiers even into the middle or second half of the sixteenth century. In a 1594 text, Sir John Smythe recalled seeing Swiss halberdiers years ago in France and took inspiration from that example for his instructions on arranging halberdiers with pikers for his imagined ideal army.

I don't want to create another thread, so I'll ask here. Where I can read a detailed description of how the swiss fought? Like, how to use a halberd in the press of melee? Or was it dropped in favour of a sidearm in that case? Also, if I recall correctly, it was used to stop horses as well, so what length it should've been? I remember some sources stating it should be a foot longer than a halberdier's head, but is that enough to stop a horseman and still be useful in close quarters?

Unfortunately I don't know of any period Swiss or German texts that provide a detailed account of the Swiss way of war. The aforementioned Sir John Smythe described how halberdiers in his ideal army would fight. That's far from removed from the glory days of Swiss pikers and halberdiers, but Smythe apparently did encounter Swiss halberdiers in mid-sixteenth-century France. Smythe wanted halberds to be no longer than six feet in total and well-suited for the blow as well as the thrust. He wrote that troops armed with such halberds could fight effectively in the press and should make blows at the head and thrusts at the face. His halberdiers were to follow the first five ranks of pikers at their heels.

Earlier, in a 1548 text, Raimond de Fourquevaux combined Niccolò Machiavelli's famous Art of War with his own martial experience. Unlike Machiavelli, who dismissed the halberd, Fourquevaux considered it an important weapon as long as it was well-made and not too light. Fourquevaux described halberdiers as being able to fight in the press in contrast to pikers who had to drop their pikes and draw swords.

Machiavelli wrote that shafts of Swiss/German halberds were three braccia (arm's lengths), which for Florence was apparently around 70 inches (1.77m). This implies that weapon overall was around seven feet (2.13m), depending on the size of the head. As far as resisting cavalry goes, Matthew Sutcliffe, a late-16th-century military writer with limited actual experience, mentioned the possibility of resisting cavalry with halberds and with half-pikes.

As far as cutting helmets goes, I don't think Smythe's instructions necessarily imply that. They certainly imply that halberd blows to the head were effective, but they could have been effective without cleaving helms (stunning, kayoing, etc.). Smythe emphasized the need for long straight edges on halberds, so I assume that's what he wanted the halberdiers to strike with, but he also noted that halberds should have a strong beak opposite the blade. It's possible he wanted blows made partially, primarily, or only with the beak, though there's no evidence for this.

The Swiss (or what we now think as "Swiss") already used large numbers of pikes (or at least long spears) well before Arbedo to begin with. At the battle of Laupen, the Confederacy forces in the centre and left were mostly armed with halberds, but their Bernese allies on the right (who hadn't joined the Confederacy by then) had pikes instead.

(I might have flipped the wings, so the Bernese could have been on the left instead. Working from memory and too lazy to check.)