ECNL games aren't submitted for rankings, and teams don't earn points for playing in ECNL showcases. So, SIC and gotsoccer don't give the full picture of what is really happening.
Here's a link to Top Drawer, which includes ECNL and non ECNL teams. TH 17 is ranked 10th in the country this month. Pretty impressive. I don't know that Top Drawer rankings are more accurate, but at least they rank all teams and not just the ECNL teams.