Welcome to the forums!
First off, this thread might be useful to you:
You might be able to find a few team ideas in there.
One team (which is actually almost the same as yours) that’s quite useful at lower levels and should generate some souls is:
Treant
Alchemist
Valkyrie
Banshee
Banner of Progress (Adana)
Having Treant traited helps, but isn’t necessary. Treant acts as a tank and also can hit pretty hard with skulls once you’ve fired his spell off a couple times. Also he removes Brown which no-one in the team uses. Should be more efficient than Finley
Out of the troops you listed, none are overly useful for souls by themselves. Basically you’re looking looking for troops that have the Necromancy trait, or generate souls as part of their spells. I believe there is a team that uses three Warlocks, but I can’t remember exactly how it worked :S hopefully someone else will be able to chip in with it.
Also it might be worth checking out @Tacet 's and @KrudlerTheHorse 's videos on YouTube, as both do some good videos about team building and have some examples for farming teams (and other generally helpful information).
Tacet: https://www.youtube.com/channel/UCWlFcnuWs5b-xq9udFzA7pQ
Krudler: https://www.youtube.com/user/cshewel