Welcome!
You sound like you're doing the right research. Unfortunately, Trackers all share a similar level of complexity. Thus, a good starter tracker is one that has the features that you need, and the interface you like. it's a very personal choice. Here's some more Linux Trackers that have gained a reputation.
CheeseTracker was based off of
Impulse Tracker which works in Dosbox, if you have the energy to set that up... Looking at the lastest CheeseTracker screenshots though, it seems to have modeled after Modplug Tracker a few years back...
Schism Tracker seems to be keeping in line with the IT user interface.
ProTrekkr is another open-source tracker, that is cross-platform, and worth taking a look at... It's an open source project originally started by Arguru, who also started other projects such as Psycle, as well as several Buzz plugins.
If you want to go next-gen though, MadTracker and Skale are your primary options, and I'd actually recommend giving
Psycle a try if you know how to use WINE... Certain versions have compatibility issues though in Linux.