Although it is categorized as Large cap in your list, I believe the Spartan Total Market fund is meant to be Fidelity's response to VTSMX/VTSAX:
https://fundresearch.fidelity.com/mutual-funds/summary/315911800
Expense ratio is 0.06.
I have Fidelity and this is correct. It is the same as VTSAX.
I have my 401k all in (100%) in FSTVX, and I'm "retiring" in about a year or so. It's a smaller portion of my overall portfolio, but I am very comfortable with risk in the short term for the long term rewards.
You really shouldn't look at one individual account if you have more than one, since that's not a complete picture of your total holdings. If you have your asset allocation figured out, then you can implement it across all of your investment buckets, and it would be easy to do if you still have your old account with Vanguard (you said your old 401k was at Vanguard, so you still have that right?)
So figure out what you are comfortable with, and you could roll the Vanguard one into a bond equivalent to balance going all-in on the Spartan index/stocks in your current 401K. Since it is probably a rollover IRA now (or can be easily), you can invest in anything at Vanguard.
If you're wanting to go aggressive say for example with a 80% stocks, 20% bond percentage, then you could set your Fid 401K to go all FSTVX (stocks) and then change your Vanguard (rollover IRA?) to be 20% bonds + whatever percentage would equal up to 80% stocks between that and the Fid account. You'd have to check into it maybe once a quarter or so just to see if it's maintaining the balance you want, but it would mean dirt-cheap expense ratios (Fid's Spartan series is generally LOW expense, and most all of Vanguard's offerings are of course), and you'd have the balance you want for your asset allocation. And that could mean that you're only holding/buying the one fund in your Fid 401K - FSTVX. (although Another Reader's suggestions are good too!)