My first reply, to your first pair of wrenches, was Mack-centric, more of a remark on it looking like they made engineers wrenches for Mack kits early, and "S" wrenches for Mack kits later.
Maybe it's just my limited grey cells, LS, but I'm not seeing anything about those four "S" wrenches that casts any doubt on dating schemes.
Reading forged-in "IQ" codes on wrenches with forged-in CHROME-VANADIUM (CV) markings and stamped with the Bonney embedded shield logos, nut and bolt standard size markings (i.e., the 1081-A and 1077-C) as 1925 is perfectly consistent with the thinking that they used that size marking convention and logo up through the late 1920's/1930 or so.
Likewise, reading forged-in "IQ" codes on wrenches with forged-in CHROME-VANADIUM (CV) markings and stamped with the plain Bonney name logo, no embedded shield, milled opening sizes (i.e., the 1079-S and 1077-S) as 1939 is perfectly consistent with the thinking that they changed to the new sizing convention and the plain name logo in the late 1920's/1930 or so. They were still using those CHROME-VANADIUM (CV) dies well up through 1942 and we even see some 1943's sneak in before the WPB extended grace period ended.
Granted, the earlier wrenches being in good, clean, rust-free condition and happening to also be "S" wrenches with "IQ" codes coming from the same vendor does look deceptively set-ish, but it tell us nothing empirical about the origins of any of the wrenches or their provenance, and doesn't break any logic of the dating scheme.
If you're suggesting that all the wrenches could've been forged at the same time, i.e., in 1925, and the early-sizes-and-logo wrenches stamped in 1925, and the later-sizes-and-logo wrenches stamped in 1939, I suppose it's possible. I just don't see how that possibility is enough to distrust the date code system. It's just as possible and maybe moreso that the latter two were forged with the same or similar dies in 1939 and stamped in 1939.
The "IQ" codes being identical (with the same placement and number of mysterious dits or dots we sometimes see accompanying date codes, including two of your examples) might make me wonder.
If I was apt to think anything outside the box on these, it would be to wonder if maybe we're wrong, or off, or too strict about the transitions to the new logo and sizing. Either coming earlier (i.e., all these wrenches are from 1925) or later (i.e., all these wrenches are from 1939) on some types and styles of wrenches.
But I would have to see a lot more of it at scale and scope to get me off the CW.