Firstly we get 144 flags a day, that’s in a 24hr period considering your using them at a rate that allows W.E to continuously refill.
S1; doing P8 L7 at 3 flags per game allows for 48 hits a day.
On average you get 7 to 10 recruits per game so lets say 8 for this calculation which adds up to around 380 recruits per day.
On average the XP is around 850 so times that by 48 and you get around 40 thousand XP a day.
S2; P5 L6 chosen randomly requires 6 flags in normal and 10 in hard. So based on 6 flags you would get 24 hits per day.
On average the recruits are 10 to 12 for normal so lets say 11 making it around 264 recruits per day.
XP on average is around 1600 so that times 24 equals 38 thousand XP per day.
For both seasons the odds and amounts decrease as you go up in levels and require to use more flags making them less tempting to farm.
Having said that s2 is far better when it comes to the amount of training and crafting items than s1 but only worthwhile within the lower proveinances as they become less worthwhile as you use more flags in the upper levels.
So where your farming depends would depend on what your chasing which is either crafting/training items or recruits to run your tc20.
Not that much difference in XP but still better in s1 than s2 and again lessens as you use upper levels in both in you count per flag results.
s1 for recruits and XP
s2 for items