I feel that the most critical step to really re-inventing those characters would be to get them away from Dynamite Entertainment.
I enjoy Gail Simone’s re-invention of Red Sonja and understand there’s a balancing act with the branding and appearance. But an ongoing thing with Dynamite Entertainment is that they stockpile old characters to use them in spinoffs, mash-ups, etc.
What would really be bold – is actually re-inventing these characters without anchoring them to bad branding and design decision made in 70s (or earlier). Red Sonja has changed far more than her costume has, and not updating her appearance to reflect that hampers the comic.
At the end of the day – the reason these properties got sold to Dynamite Entertainment and the reason this is the second time Red Sonja’s been re-invented since then is because the old branding isn’t speaking to audiences today.