Personally, I'm on the side of trying to achieve knowledge transfer between the generations. This can take two possible paths. One is that emergency management professionals in leadership positions should be coaching their junior staff on what to do, what works and what has been tried in the past. You could have little mini-tabletops with them to talk through different situations that you faced in the before. Here's one for example, You are activated and one person who represents a primary agency refuses to come into the Emergency Operations Center (EOC), saying they can handle the situation from home, over the weekend. What do you do? What are your courses of action and what are the ramifications of each?
If you don't have a supervisor willing to dedicated that type of effort to your career development, you can approach other "senior emergency managers" and seek a mentor relationship with them. A monthly coffee chat or occasional phone call to discuss this or that situation you are working through might be another way to get some advice that doesn't require all your wisdom to come from personally making all the mistakes yourself.
The sink-or-swim mentality is what I see happening in the majority today. It certainly is a trial by fire!