Firstly, Monte Carlo simulations (such as on https://www.getguesstimate.com/ ) is likely more precise/useful than pure Fermi estimates, as they make uncertainty, including your consideration of the value possibly being off by factor 10, explicit and thus you can have greater confidence in the results. One advantage Fermi estimates definitely have is that they force you to think about the different components of the problem, or in this case how different careers contribute to your impact. But they are generally speaking primarily helpful to estimate orders of magnitude, and are thus not all that useful in comparing different options unless they lie very far apart.
Secondly, I agree with shawzach that it makes a lot of sense to talk your career considerations through with other people. I used EAGx Virtual for that purpose and looked for all the people who might have something to contribute to my career considerations. But then again, it differed from your situation in that I didn’t have several alternatives but rather one preexisting plan and wanted to figure out whether it was “good” or I should look further for alternatives. Still, people might be able to add a few crucial considerations or just arguments you hadn’t thought of before that affect your estimates.
Firstly, Monte Carlo simulations (such as on https://www.getguesstimate.com/ ) is likely more precise/useful than pure Fermi estimates, as they make uncertainty, including your consideration of the value possibly being off by factor 10, explicit and thus you can have greater confidence in the results. One advantage Fermi estimates definitely have is that they force you to think about the different components of the problem, or in this case how different careers contribute to your impact. But they are generally speaking primarily helpful to estimate orders of magnitude, and are thus not all that useful in comparing different options unless they lie very far apart.
Secondly, I agree with shawzach that it makes a lot of sense to talk your career considerations through with other people. I used EAGx Virtual for that purpose and looked for all the people who might have something to contribute to my career considerations. But then again, it differed from your situation in that I didn’t have several alternatives but rather one preexisting plan and wanted to figure out whether it was “good” or I should look further for alternatives. Still, people might be able to add a few crucial considerations or just arguments you hadn’t thought of before that affect your estimates.