The issue is that the current champion doesn't match any full casters under the paradigm of anything but 6-8 encounters with 30 combat rounds and 2 short rests per long rest.If the Champion subclass is the baseline paradigm for the Fighter class, then their match would have to be one of the full spellcasters. In both 5e and 5.5e, a fullcaster would be the Bard, the Cleric, the Druid, the Sorcerer, the Warlock and the Wizard. Which one is their match now?
There was no wiggle room created to offer Martials to have basic, advanced, and conplex options in the baseline.
This is why A5e had to cut major bits out the 5e Fighter to create wiggle room for the A5E Martials.