Factions should not counter other factions...each faction should have at its disposal the ability to counter any specific game element...
It may turn out that one faction has a stronger counter to a specific element (ogrovs are the best anti-module ship), but in principle faction A should not be the counter to faction B, and faction B should not be the counter to faction C....
If the TEC rebels simply cannot counter the loyalist Titan, then either 1) the loyalist titan is too powerful and/or 2) the rebels are severely lacking in a certain element...
Since the rebels pretty much have the same ships as the loyalists (Titan being the only meaningful difference), then either the rebel's titan is not good enough or the loyalist titan is too powerful...
It's perfectly fine if one titan excels in one area while another titan excels at something completely different...but if the rebels continually are being beaten back the loyalists, the solution is not "well, the Advent will beat the loyalists so there, no problem"...