To expand on my post from earlier, realistically I don't think that you really need to have more than one gyuto, unless one is a ridiculously thin laser and the other a workhorse. I have two on me that are both great cutters, and are nice to have around. Its nice to have a backup for when an edge fails, but thats pretty rare. I imagine most here rotate a few gyutos because they have few gyutos.
i own multiple gyutos but on a given day only use one
It's interesting that the gyuto is, by definition, supposed to be an all-rounder type of knife: one that works very well for many things, but is perhaps not ideal / the absolute theoretical best at any of them.
But, the condition of knife knerdom and acute sensitivity to details (and a desire to rationalize more knives) leads to owning multiple gyutos that become more specialized / better at particular things. Ironically this make them less gyutoy as improving their performance at one type of task is often at the detriment to their versatility / performance at another.
When I'm selecting which gyuto I want to use for a particular set of tasks I usually just try to match the requirements of the task with the virtues of the knife, but my mood and what strikes my fancy also influences my selections. Also, optimal technique for an identical task done with 2 different knives will be different and I like the variety and discipline of attempting to master multiple techniques.
Usually four. Usually three 240-250mm and a 270mm. I don't like 210mm gyutos, prefer to use a 210mm petty.
Lots of reasons to pack multiple gyutos: I already own them, different grinds are better for different tasks, nice to have a carbon knife sometimes, nice to have a stainless knife sometimes, nice to have a knife you can lend out to worthy coworker, nice to have a backup gyuto with a fresh edge, nice to use whatever strikes your fancy that day.
"God sends meat and the devil sends cooks." - Thomas Deloney
Ideal work setup for prep - 1 Lazer (210 Suisin Inox Honyaki or Kono White 2) & 1 Hammer - (Hiromoto AS 240), 1 Stainless Beater always good to have around - Togiharu Hammered Damascus 210, Fancier/Delicate ones on lighter days. Only Gyuto to come out for service is a 210 Misono Swedish (already short in height OTB) that is pretty much a 200 suji by now due to sharpening over time.
240 Yoshikane SLD gyuto/kiritsuke and Asai 240 AS gyuto/kiritsuke. The Yoshikane is a great knife but the profile is flatter then I prefer for some tasks (like slicing meats on the board) so I added the Asai which has more belly (closer to a traditional gyuto profile but with a bad ass looking tip)
Rule #1- Don't sweat the small s%&t, rule #2- It's ALL small s%&t
Sab nogent 10" and a vintage k sab 10". Doesn't sounds like much, but those are the chefs knives I use at work. Though the reality is that I generally always have 4 cleavers in my kit, at the moment it's a Hattori FH, Sugimoto #7, Fujiwara Teruyasu and a beater for splitting ducks, ribs, chicken wings etc.