A soul generating “team” is an, at least, semi active guild.
A guild with some higher ups (like level 400+) who spend good money in the guild tasks because they have their kingdoms maxed out. 3-4 active ones of those are enough.
Just say what you need in the guild chat, otherwise they may only/mainly go for special keys.
If you are an active person yourself they’ll be happy to help. Even if you don’t attribute to the guild tasks (you should concentrate your gold on your kingdoms)
From the guild tasks you get souls but those are not high in number, more important are the gems you get. Once you used the gems to buy the two best gem-armors (500 gems each; one with +100% souls and the other with +100% gold) you collect the gems again to 500 and buy the 18k souls cauldron from the shop.
If you do the events which give gems as reward too, then you should be able to buy the 18k souls every two weeks.
This doesn’t require you to have any specific troops, traits, weapons, whatever or to spend time to farm souls which is tedious at your level.
For a larger number of souls you’d need The Dragon Soul (took me ages to get that thing - the keys from guild tasks help here too) and three troops with an active necromancy trait to max out the soul limit.
I’m level 600 and get 320 souls per soul-farm-battle but it bores me so quickly, that I have no patience to really farm large amounts. 3-4 battles and I’m fed up ^^ I’m no farming/grinding person.
I only do it when I’m short of some and need to max a troop.
As for pvp: when I started, I built up a Goblin team. I find them easy for beginners, they normally give you an extra turn and an complete Goblin-only team from Zaejin gives good boosts too.
Later I switched to Undead because they have troops that give souls.
The soon I had 4 dragons from Dragon’s Claw I made a team of them and they rocket in pvp Had a lot of fun with them for a long time.
All I had back then was Dragon Eggs, Baby Dragon (used those two as fodder, not casting them in battle unless there wasn’t much else to do or my tank - the egg - was about to die), Dragotaur (that one’s an important key troop) and Dragonette. In that order.