when posting TO&E questions, it is best to post in the TO&E sub forum. Also, it is a great help to give the formation numbers as found in Mobhack, and also if discussing units, the number and/or unit class number. Otherwse it can take 10 minutes fiddly searching to find the things.
Generally speaking, if an infantry unit is over 4 men, it does not justify size 0 except in very rare cases. (SFMG groups are of course almost always treated as size 0, as are small AT guns. That is also a design decision).
In this case, it is because it is as I recall from the design decision of maybe 4 years ago, a 5 man team with an LMG. It carries the second LMG of the section, and makes up the numbers to the correct TO&E amount.
Unit 163 in OOB 12, is a 4 man team which is
just on the borderline where you can justify size 0 for a team. You could therefore call it either way as a size 0 or size 1, we chose 0 there.
Unit 274 in OOB 16 is 5 men, which is just over the limit to justify size 0. Then, since it is size 1, it does not get the points addition for size 0, of course!, so is cheaper
look at unit 285 in OOB 16, which is a 3 man gun group. It is size 0.
So not a bug in the data, therefore no fix required. It has been that size for 4 or 5 years. Naturally - if you think different (whether the US one should be upped to 1 or the GE one 0), you can Mobhack your OOBs to suit your POV then run the points calculator.
Cheers
Andy