dont farm experience unless you are level 500+
gold is better farmed by fast killing in pvp (ranked and casual)
so you make a team that kills fast not a team with “merchant” traits
about souls best case is to stuff The dragon Soul in all your teams, it just pays off a longer shot (or any other soul generating troop really)
here is a whole collections of teams
and no, there is not such thing as “one best team” for either
it all depends on your play style, available units, enemy difficulty, and the units stats
some teams will work early game when you and your enemy stats are low, some teams will start working only after your magic goes high, etc