I just finished the course, it was awesome!
I didn’t put this together until I watched Brian’s case study, but should the 3 fund portfolio apply to all your Accounts as a whole? For some reason I was thinking each account you would apply the 3 fund portfolio individually, but for Brian his 401K was all SP 500, so International and Bonds made up the other (IRA?) accounts.
Also, I am not very good at math and adjusting percentages, I can see why TDIF is recommended!
In general the answer is it’s not a big deal! You can definitely have a three fund portfolio in EACH of your accounts. i.e. Your IRA can have 3-funds and your 401k can have (possibly the same) 3-funds.
OR you can look at your accounts more holistically. In Brian’s case study, his 401k only offered a good US fund, so he balanced out his portfolio wide three-fund portfolio in another account.
Either is totally fine. There is some VERY SLIGHT benefit to doing “tax efficient fund placement” if you want to try to get tricky, but it’s really not a big deal. Here’s an article that talks about it:
https://www.bogleheads.org/wiki/Tax-efficient_fund_placement
Thank you Jeremy for replying!! Appreciate different suggestions for how to achieve the same thing, thank you!
I finally understand the tax efficiency article now… after I had some down time and read some more things about Bonds-
Do you know what kind of bonds are in TDIF? Reading below it looks like Series 1 and Municipal Bonds are ‘safe’ for brokerage accounts.
I’ve read a few places that bonds are not ideal for brokerage because of taxing, I read one suggestion to manually create 3 fund portfolio and put your bond allocation in tax advantage IRA account to shield from tax impacts 
Do you think tax impacts for bonds in a brokerage is substantial enough to worry about?
I guess if I’m that worried about it I can hold off on bonds for a bit and be aggressive with 100% stocks starting out…