With low tech you can only win against Ordos wimmthat have poor equipment. If you go against a full ordo that has decent equipment (sabots, needlers, tachyon, etc...) The radiant with his escort will destroy half of your fleet.
As others already mentioned low tech can handle the standard ordos.
It can't stack them like some of the stronger fleets and it was a massive pain trying to go up against tesseracts, but plain remnants aren't a problem.
I think later on Onslaughts are even some of the better anchors against radiants, buffed TPCs are extremely good and if you can get some omega Ms it's a long range shield suppression powerhouse.
Dominators do kinda suck though IMO, have to make do with Enforcer spam + a few Monitors/Kites/whatever you like.
The 1 thing I do dislike is SO on Brilliants, decentish cruisers running around at ~150 is a massive pain.
If you miss it when ordering a gangbang on a ship caught out of position next thing you know is a decent chunk of your fleet is on the other side of the map on a wild goose chase.