Here are my suggestions.

How to do?

If you just sold your Vanguard funds and you like the allocation, you can replace them with Fidelity equivalent funds.  One to one replacement, no need to do dollar cost average since it is a sideways move.  You only need to use dollar cost average method with the new money since the equity market is at or near all time high.

As you are looking at Fidelity Total Bond Fund (FTBFX), I would suggest you to use a short term bond fund in your bond investment.  FTBFX has a duration of 5.63 years.  In current interest rate normalization period, it means that FTBFX will lose about 5.5% for every 1% rise of the interest rate.  If you look at the total return of FTBFX, you will notice 2009, 10, 11 and 12 that the fund gained a lot due to the interest rate going down to near zero.  Good luck.