I have several smaller suggestions to improve gameplay on mobile.
Allow more than three levels to choose from when selecting a delve. The current system makes it hard to do the faction team delves after getting to certain difficulty with another team.
Allow sorting by ‘Newest’ in troops so you can find troops you just got easier
Make more diverse hero types for the classes. Some types are represented in multiple classes (i.e. Demon, elves, undead) while some troop types do not have a class at all.
Allow trading of items and resources between players. Not something global like a marketplace, but something between guild members or friends, if that were to also become a mechanic.
I know there are other small things that I can’t think of right now, so I might add to this later as things come up.