> But I do think its fair to say that the scale of Discord is 5x bigger while having 1/10th the employees and the last valuation round was at 2 billion versus slacks 12 billion valuation?

Slack has revenue, probably 100-1000x that of Discord. It's a real business and not burning VC/Tencent money, which is exactly why it (imo correctly) has a much higher valuation.