I would not call any of the dwarf retics small, nor would i call scrub pythons small. this taxon really is for the serious collector with the resources to properly house, feed, and heat these large constrictors. Retics are much more alert and active than Burms, balls, and boas, so they require respect and experience, not a beginner snake.
That said, most dwarf races are not exceptionally snappy by nature if captive raised. Relative sizes will vary, but a twelve foot "dwarf" as a mature adult of six or more years would not be unexpected, especially a well fed CB female. This is still far smaller than most other retic morphs.