Soooo. I have a named thrall from some.settlement on West coast…4000 health or so and levelled up to 17…but still seems weedy compared to dalinsia or beast master from exiles so how do I get a dalinsia type?
From purge? Summoning from shrines? Or are there some in the wild?
Try the accursed camps.
Accursed berserkers is a good start. Eventually you will find named berserkers like Dalinsia and others, many others wait for you on accursed camps like @darthphysicist just told you. When you hit lvl 60 with epic or legendary gear try the Citadel, the loot and the thralls are unique.