> There isn't public information on this, but in the past I have heard that Chrome had a lot more engineers than Firefox (though it's a bit difficult to make direct comparisons because of scope differences). I suspect that's still true. I also heard the same thing about Edge at one point, but I suspect that may not be true now.
Scope differences make it incredibly hard.
Plenty of people on the Blink team work on things like Skia, which neither the WebKit nor EdgeHTML teams have equivalents of (because they just leverage OS-specific APIs), or on their HTTP/TLS stack (again, neither WebKit nor EdgeHTML teams have equivalents of), etc.
Gecko is somewhere in a middle-ground; they rely on third party libraries (including Skia—does that make that part of the Chrome team Blink/Gecko developers?) but not quite as much as WebKit and EdgeHTML do.
Core web stuff? The Blink team is larger, yes, but by how much is a hard question.
FWIW, I believe the Gecko team is nowadays larger than the EdgeHTML team, but they're certainly close in size. (And close to the size of the old Presto team, which admittedly had a scope closer to that of the Blink team.)
The Chrome team has a lot of its own infra due to policy that a lot of Chromium stuff be public (its bug tracker system now code.google.com is dead and its CI infra are all done by the Chrome infra team).
I imagine to some limited degree it's true for WebKit (though I suspect they don't have anyone whose sole job is infra) given Apple don't have any general public bugtracker or CI system, and totally untrue for Edge.
Scope differences make it incredibly hard.
Plenty of people on the Blink team work on things like Skia, which neither the WebKit nor EdgeHTML teams have equivalents of (because they just leverage OS-specific APIs), or on their HTTP/TLS stack (again, neither WebKit nor EdgeHTML teams have equivalents of), etc.
Gecko is somewhere in a middle-ground; they rely on third party libraries (including Skia—does that make that part of the Chrome team Blink/Gecko developers?) but not quite as much as WebKit and EdgeHTML do.
Core web stuff? The Blink team is larger, yes, but by how much is a hard question.
FWIW, I believe the Gecko team is nowadays larger than the EdgeHTML team, but they're certainly close in size. (And close to the size of the old Presto team, which admittedly had a scope closer to that of the Blink team.)