I imagine they likely aren't related, at least not directly. Could have played an influence on why they did a challenge coin in the first place, but I'm not seeing any serious overlap in design and symbolism, besides the skull itself, and unlikely the flame and crown. Not saying they couldnt be related, but I wouldnt bet on it. It was a good possible lead, but I don't think itll lead anywhere. But thats just my opinion and analysis. Someone else might see things I dont