Yes the funds are 0 fees and Fidelity loss leaders. They are good options if you plan on keeping your money with Fidelity or for money in retirement accounts (because you can sell and transfer without incurring taxes).

I believe FTIHX is close to FZILX similar to how FSKAX is close to FZROX. With just the two you are diversified across the entire world stock market so they are all you need. Whatever you pick they all have very low fees so you can’t go wrong.