Answer architecture round 1: Main draws the CLI's default seed and passes it to run, New names every option mistake at once, dataGiven says what it is, and the docs drop seeded where every sequence is

README.md

@@ -372,8 +372,8 @@ links all of them. Two locales, with `enus` from `github.com/larvit/fejkdata/dat
 are `WithDataFS(append(svse.Modules(), enus.Modules()...)...)`. To stand in your
 own places, pass the locale's `FS` alone beside a tree providing `geo.SE.address`, a record
 with a `format` and the columns `sv_SE.address` reads, `street`, `street-number`,
-`postal-code` and `locality`: `WithDataFS(svse.FS, myPlaces)`. `New` fails where no `WithDataFS` or `WithDataPath` names the
-data to load.
+`postal-code` and `locality`: `WithDataFS(svse.FS, myPlaces)`. `New` fails where no `WithSeed` gives the seed, or no
+`WithDataFS` or `WithDataPath` names the data to load.
 
 `New` refuses data that breaks the grammar, could mean two things or cannot render a valid
 value, and `NewTemplate` refuses such a template. A category of an indexed source is
@@ -430,7 +430,7 @@ first call for a type compiles its tags and reports what they get wrong, with th
 error on every later call; a `datatype` in a tag other than the one its Go type sets is
 refused, naming that type.
 
-A `*Generator` is safe for concurrent use; a seeded sequence is reproducible only
+A `*Generator` is safe for concurrent use; a sequence is reproducible only
 when drawn from one goroutine. Changing how a value is composed shifts the seeded
 stream for that value and everything drawn after it.