More than anything I think you need to fight to your own strengths, Rousey was and probably still is an excellent dangerous grappler but we've only seen that recently when Cat forced an opening on to her.
The problem I think was that the fear factor of Rouseys grappling and indeed her opponents not being great strikers(and indeed Rodna herself having a good chin) allowed for a fantasy to build up around her that she was a good striker. Yeah she had power(not impossible she catches Nunes or Holm on a given day) but defensively she was always really poor and looking to go out and focus on striking against quality standup opponents was always going to be highly questionable.
We see some MMA fighters who narrow there game as there career goes on and end up hurting there performance up at least guys like BJ, Rampage, Anderson, Fedor, etc focus in on something they do well at the expense of a formerly more diverse game, Ronda focused on something she does badly.