General mud is asymmetrical without giving either side a major advantage - proving the general possibility to do this. Pavlov's house did not do a good job in my opinion. Consider this - if you play OKW and want a good place to put your schwer truck, from the south spawn you are going to get an amazing position holding the corner fuel and don't have to worry about long range fire from tanks or AT guns because of the shot blocking and vision blocking terrain combined with the security of being in the corner of the map where you only can be attacked from 2 directions anyway. From here your truck will be able to hit opposing units from any direction at range. From the north you don't have anything like that available. If the map designer didn't actually want to give both teams an equal opportunity for this fuel point, then he should have included a 3rd fuel point where the north side had an equally weighted advantage, and let teams fight it out over the more fairly balanced center fuel point for fuel superiority.
As it is, south gets corner fuel automatically if the south team is competent. Then both sides fight over the center fuel, which would be better balanced except now south has an advantage in this fight because he has more fuel coming in than north does to spend on his units.
If we could look at statistics for win rates based on spawn position I am completely confident that the numbers will prove this to be the case - unofficial numbers from my own observations definitely say so but this is not official and I don't expect you to just take my word for it.
Nearly everyone will tell you that Redball is basically the best 3v3 map. Redball is also basically symmetrical - There isn't really anything on that map that isn't equally available to both teams. Why is Redball not boring then? Because the map is balanced and both teams have equal chances on it. It uses visual effects to achieve some variety without putting a lot of objects in asymmetrically that actually have an effect on pathing, vision, and ability to direct fire onto a point.
can't comment on red ball express. it does look symmetrical and great, but never had a competitive match on that map. maybe when it gets added to the automatch. so i agree symmetrical and interesting maps exist.
it seems as though you are interested in equal opportunities for each and every resource points on their own instead of like me, who'd rather see equal opportunities uneven on several points on the map but eventually well balanced out overall. seeing how you used red ball express as an example, i think it is safe to assume that you relate equal-opportunity to equal-distance... like in steppes. but combine that equal distance with abnormally openness of steppes, that equal distance actually gives kubel an extraordinary advantage at the very start of the game by either forcing a retreat on the first one to units by catching them off guard or making smart players avoid the island all together until a few more units arrive. which will give mg42(s) a plenty of time to set up. what if the point is symmetrical but green covers are set in a way that a battle will occur at long distance. wouldn't that favour axis overall?
I do agree that red ball express looks interesting and symmetrical but symmetry doesn't equate to balance as long as factions are asymmetrical.
by the same reasoning of how far right fuel is favoured towards southern team, the centre fuel is favoured towards northern team. after all, the southern side of centre fuel has shot blockers and movement blockers than northern side just does not have.
as you said, i have seen many times where one okw player on the southern side planted himself up on the far right edge many times. this would have been a problem if pavlov's house was a 4v4 map. but it is 3v3 map and has the size of semi-big 4v4 maps. the allies can use the ample space to maneuver and strand okw player. which can never happen in ungodly sized maps like shittlebruck, lienne forest 4v4 etc etc.
imo, the best thing map makers can do for 2v2+ map balance is not trying to guarantee equal opportunity all the time, but to allow players to use their resources most effectively... as in no pathing issues, ample size, rooms to maneuver etc etc.