Virginia Union is a alliance of SYC and McLean, but as the ECNL club, McLean holds the charter. It's been a big plus for SYC's top girls, who now have a pathway to an ECNL club. For boys, it provides a pathway to an ECNL club if they don't make SYC's MLS Next team.

I have 2 boys U11 and U14, we went to tryouts for all 4 teams. I was impressed the most by SYC overall. Very strong player pool.
Their U14 3rd team (NL EDP) could probably beat many U14 ECNL-RL teams in the area, even challenge bottom-dwelling ECNL-NL teams.

The one misfit in your group of 4 is McLean. The other 3 are among NoVa's best clubs, McLean is in the second tier. Union can't stay competitive with McLean's organic geographic player pool, so they need to draw in SYC and other kids to stay competitive.

We went to two clubs in NOVA. Seemed similar to what I experienced last year.