Physics is like this too. An odd thing about physics is that it doesn't have very many of its own techniques or tools, so we have to go outside of our field if we want to solve any nontrivial problem -- theoretical or experimental. For instance I didn't take any electronics or programming classes beyond "101" level, but have ended up using both extensively in my later work.
At my present workplace, I've noticed that the people who have polymath tendencies tend to have physical science degrees.
Physics is one of the least systems oriented sciences. It is also the easiest science when it comes down to brass tacks. Because physics can make so many simplifying assumptions, it has very few tools to tackle systems. Most physicists I have met have the least capability of anyone I have met when it comes to systems thinking and have the most narrow mindsets and approaches.
I don't doubt your experience. But it seems odd, because the people I've known who were the best at "systems" and multidisciplinary thinking were physicists and physical scientists, including myself. My title was "systems engineer" for many years, and they finally let me be "scientist" though I do mostly the same work. I work in measurement instrumentation, at a site that has mid-sized engineering and manufacturing departments. I'm often the first and only person to fully grasp how a product works, when it involves optics, electronics, mechanics, computation, and the application domain, and has to be manufactured with high quality.
The thing is, the limitations of our tools don't excuse us from having to do research and make things work. Or from finding employment. ;-) So we tend to be opportunists in terms of synthesizing knowledge from multiple fields.
Physics and math have been together for a long time, they have high levels of cross-pollination.
Somehow, this was extended to computers too. The three of them are now cross-pollinating. It happens with other sciences too, but it seems it started earlier in physics and math.
In that sense, anyone with knowledge consisting of "a little bit of computer science plus one single other trade" likely represents the new baseline, not polymathy (similar to the previuous one "a little bit of math plus one single other trade").
So, if you want to be a CS polymath, you'd have to know what CS will look like when all this cross pollination settles down. I think it will look very different from what it is now, it is such a new science. Impactful, but very new.
Even biology had this cross-pollination thing. Lots of fields took evolution ideas, some in very dangerous ways. This influence survives to this day (neural networks, evolutionary algorithms, etc), but it is more like a cargo cult than real intersection. It resembles more biology from the past than what biologists think today.
Polymaths right now are probably working in the fields with less computers, trying to fill that gap. In the cross-pollination analogy, they're the first to waggle dance.
In that sense, I see a history+biology polymath more rare and special than a cs+math polymath, for example. They probably have a more unique and singular perspective on science than the more estabilished swarm of existing cs+math polymaths.
Indeed, I think that in some sense, physics and math (and maybe astronomy) were all born together. The Pythagoreans thought that they were discovering the secrets of the universe. Aristotle wrestled with the difference between physics and math, for instance between an ideal circle and a real physical one. Physics was always an exploration of what aspects of nature could be described mathematically. Development of calculus and differential equations gave physics a gigantic boost. We always want to try out the new toys.
As I mentioned in another post. physics ran out of problems that were solvable by hand with equations roughly a century ago. Feynman managed rooms full of "computers" who were people operating mechanical calculating machines for nuclear physics problems. When digital computers gradually became available, physicists were already waiting in line to use them. Von Neumann promoted government funding of academic computing facilities with an eye towards using the computers for bomb yield calculations.
The software industry gradually began to emerge roughly a decade later.
Ironically, I was "a little math plus some other trade." I learned programming in high school (1981) but had a summer internship at a computing facility and it didn't spark my interest in programming as an occupation, so I majored in math. My other intended trade -- being a rock star -- never materialized, and I ended up with a second major in physics instead. But I've always been an avid programmer, and I do most of my computational and experimental work by coding. All of my fellow physics grad students were coders, and many went into programming when their luck ran out in the grim physics job market.
I don't disagree with this characterization of studying physics, but there is a very noticeable tendency for physicists to expect their expertise to transfer to fields they are very definitely not experts in. (Not exclusive to physicists, obviously, it's just a lot of public science communicators are physicists.)
EDIT: Most noticeably from the absolute garbage code I had to make work that these 'genius coders' produced. They were good at physics, but they should never have written any code if it could have been prevented.
EDIT#2: And an adjacent poster "FredPret" demonstrated it perfectly. Let's derive Evolution from particle physics... and go! (Sean Carroll is a good antidote to this attitude... he knows there are levels of description that are useful.)
It's certainly not exclusive to physicists. The syndrome is called "engineer disease," maybe just because engineers outnumber physicists.
Garbage code isn't exclusive to physicists. The coders often complain when they have to deal with code from other coders.
And physicists gonna code. The last nontrivial problem to be solved without computation was probably solved sometime in the 1930s. And the most powerful "physics software" is a coding stack.
In my own case I've made a career long effort to learn good coding practices, but I don't expect my code to go straight into production.
As for deriving evolution from particle physics, I don't think I've known a physicist who would recommend that.
At my present workplace, I've noticed that the people who have polymath tendencies tend to have physical science degrees.