Machinist vs Summoner vs Red Mage vs Reaper

[MahthildisMMORPG]

Which class requires the less amount of brainpower, combos, and/or mandatory specific burst windows?

And which is easier to hardest?

All these classes are the only DPS to be top tier at all the Deep Dungeons (excluding Rper, only top tier at POTD)

So I'm like, if I can main one of these, I'll pretty much be set for all content I like, and learn it for things other content (like endgame, savage, etc). So as a person who loves Dancer, yet its mid in deep dungeons and PVP, I'm at a crossroads, while also feeling iffy about Machinist due to having to think for proper burst windows which can be screwed over by ping or a small mistake in the rotation.