Hmm, could you share with us a few of your builds for the ships you've tried? Fully officered remnants are quite powerful, but a player fleet Paragon should beat an AI radiant 1v1. In general, one trap to avoid is using too many big ships: remnants love to swarm because they are so fast and mobile, so if the player is too outnumbered then they are just going to get picked to pieces. I'm a fan of 1 or 2 capitals + many destroyers or high performance frigates (8-12 DP range ships). Gets a nice big ship for duelling radiants and then a lot of mid ships for numbers and hunting enemy frigates/destroyers.
Paragon
2x Plasma, 2x Tach, 2x Heavy Needler. 2x Grav, 2x salamander and some PD. HS, UI, Front shield conversion, Resistant flux conduits. With built ins comes out to 58 caps/60 vents. Officers have applicable skills, both aggressive.
Falcon(p)
4x typhoon reapers, 2x small sabots, 2x burst pd with hardened shields, ECCM package with 2 steady missile spec officers. Flux 15/15.
Tempest
Phase lance, pulse laser, breach or sabots with HS and ITU built in and hardened subsystems. Most officered. Flux 2/20.
Harbinger
2x Ion pulser, 1 Heavy Blaster, 2x Burst PD with UI, Resistant flux conduits and EM. No officers. Flux 14/6.
Astral
2x Squalls, 2x Grav, few pd with EMR and expanded deck crews. One officer for one Astral. Fighters 2x Longbow 3x Dagger 1x Broadsword. Flux 15/16.
And some shrikes(p) and Fury class with stock "Attack" autofit, Sunders with stock "Assault" autofit. No officers.
Flagship is 4x AM, 2x Ion Pulser, 2x Typhoon Reaper Doom with ITU and Heavy Armor built in, Resistant flux conduits with most points dumped into capacitors. New phase ship has a similar configuration but with 2x plasma, 2x heavy needlers, 2x Disentegrator and 6x small sabots.