Just to, uh, step in here.
Both Sirrian and Nimahin often run late game accounts for testing purposes. However, these aren’t their preferred accounts, or the ones attached to their developer handles. (Especially because if they pulled a mythic on an endgame account and everyone knew it was them, global will typically try to drag them in. :P)
Nim specifically wanted to come on and play Arena, or run more unusual teams in PVP. That was her goal from streaming.
So, I just wanted to clarify the point about both of them having frequently played on endgame accounts. If you want to ask them more about this, I’d recommend submitting a question in the Dev Q & A thread or tuning in for the next stream.