Last try, with pictures so no excuses.
Two first were berlin matches, only used infantry, never used engineers. (to make it simpler, calm down i use engineers)
1500 score gets 1652 xp, around 1.1 ratio
2289 score gets 1913 xp, around 0.83 ratio
2157 score gets 2090 xp, around 0.96 ratio
This second game i played each squad (used same ones) only once, then i watched youtube for 11min, so i barely played 7 min. (13k xp, divided by 7 min gets you bonkers 1800xp/min)
You can clearly see worst ratio is around 1, with 1104 score, with 1000 score team geting 1200 xp, clearly 1.2 ratio, not so high, but compared to 0.83 is actually significant.
Still i got to much score to highlight this problem, so i played axis tunisia with junkyard weapons and did like 5 kills on infantry squad just ot get lowest score.
Here it is:
420 score (nice), gets 893 xp, MORE THAN DOUBLE yee
But it gets better
225 score (shitty carcano 5 kills in 1 min) , GETS 727 XP, THREE TIMES RATIO
It’s consistent with dozens of games i played and checked it. Lower score, better ratio of score to xp conversion.
So in short less You play, more xp per score you get