If your Max HP is 2000 or less, a single shot from Lex will put you within execute range. With a headshot this goes up to 3000HP, and With Death Hastens these numbers become 2800 and 4200 respecticely.
Inara is a time sink for you because she has too much health and damage mitigation. Though you still counter her because Inara is weak at long range and she's not mobile enough to chase you down.
Dredge may have good long range damage but he is very bad at dealing with flanks up close. It's best if he doesn't see you flanking him so a champion such as Skye is best.
Maeve isn't actually strong aginst Maeve ,Inara has the slow deployable which slows in a short radius around her. This doesn't always work because it is stupid to verse a inara all by yourself when your maeve.