I am somewhat biased by having been through the Australian system where cronyism is alive and well. If you have 4 or 5 years you really only have 2 years befor

I am somewhat biased by having been through the Australian system where cronyism is alive and well. If you have 4 or 5 years you really only have 2 years before you have to switch to low risk if things aren't working out to give yourself time to get enough papers out before you need to apply for the next grant. What I did when I was an academic was spend 70% of my and my students/postdocs time on low risk activities and 30% on high risk. This keeps the risk down and still allow for some dreams.