Among the most easily debunked claims is that later Roman Emperors, and their coins, contain reference to being “Christian” because of Greek “CH” symbol. Greek was an important langauge in the Roman world, particularly in academics and other “high class” areas much like Latin is used in Law and Science and Philosophy today. Christ is a Greek word meaning “the anointed one” and at the time Roman Emperors and later even some of their family and certain others, had started doing the “Living God” meme.
What other term would you expect a Roman God/Emperor to adopt? IIRC there are other (pagan) Greek culture reasons why a God/General/Emperor might adopt the “CH” meme.. Also common on coins was mostly two (father and mother?) (not the 3 seen at many churches) crosses. The Egyptian “life” meme was also common, and many of these crosses have curved and tapered bottom leg and short side legs and look much more like the new sword with hand guards that had just become the new better design due to improved metal working. Archers might have been more deadly but even today no one speaks in terms of “we will take the nation by the fighter-bomber” but “by the sword”.
The above is a lot of unsupported speculation, but guess what is also and unexplained unsupported where there SHOULD be tons of “support”? The idea that the “CH” and simple crosses lacking any “Jesus on Cross” were anything but long used common pagan versions of simple pictograph symbol language.