Two thoughts, even though I will probably get jumped for expressing them:
1. In HEMA, is the emphasis on "Historical" or "Martial Arts" ? I.e. do you practise it because of interest in the past (be it the C14th or the C19th), or because of a desire to learn a fighting art (for whatever reason: fitness, exercise, self-defence, self-confidence, discipline, stress-management, recreational value of fighting without getting arrested as BD once wrote...).
2. Most HEMA streams are not living traditions-- there is no living continuous school of longsword, pollaxe, rapier, Ringen, pugilism; even the military sabre and the "canne" transformed into sporting forms (in the last century: there must have been British or German or French men alive in the 1950s who had learned how to fight with a sabre or sword, say the pre-1908 style British military swords, with a serious view to hand-to-hand combat). HEMA are reconstructed by scholarly research, and are young: 20 years at most ? First generation.
In contrast Eastern Martial arts are, for the main part, living traditions— even sportified or prettified or ossified...Likewise, BJJ or say Krav Maga are in their second or third generation and hence have tradition, transmission, and experience, that have streamlined practice and teaching and weeded out bad practice and improved the art.
So to practice (only) HEMA means something a bit different from eastern Martial arts-- it's experimental, historical, scholarly, bookish:viewtopic.php?f=3&t=17759
The consequence seems to be that to practice HEMA must affect all the martial arts aspects (fitness, self-defence, etc): you can't just do it as you would learn judo or karate; you have no master or tradition to fall back on, but you're constantly innovating and trying to find out something lost. Is that fair ?