Is it technically possible for the balance modding team to limit certain units depending on the game mode?
Not as far as I know.
Right here:
https://www.coh2.org/topic/61229/resource-income-per-game-mode/page/1#post_id609470
and there not "mythical", they are quite reliable and tell a different story than your theory.
"That said, the difference between 1v1 and 4v4 is smaller than I expected (around 200 fuel after 60 minutes). Also, it is noteworthy that before about 14 minutes the fuel incomes is slightly lower in the larger game modes. "
Nothing against SiphonX, but the data shows weird oddities that do not make sense. You cannot use it as an argument.
MP earnings of below 100 for 3v3 and 4v4 within the first 3 minutes? 1v1 and 2v2 generate MUCH more FU and MUN income in the first three minutes, while 4v4 stays at the base income and 3v3 slightly elevated above the base income? This would mean that in larger game modes, there would be next to no territory captured in the beginning. No mode generates a CP until after minute 6? This makes me believe that the binning logic he uses has some inconsistencies.
Additionally the cumulative graphs say the FU/MUN income in small modes were higher early on (which does not make sense as stated above), while the per minute income in large modes is higher from the second bin onwards.
This data has clearly issues.