That saying had nothing to do originally with makers of suits. Dorothy L. Sayers refers in her Lord Peter Wimsey novel The Nine Tailors (Victor Gollancz, 1934) to the custom of ringing the bell in the Fen village church when there was a death:

"Toll-toll-toll; and a pause; toll-toll-toll; and a pause; toll-toll-toll; the nine tailors, or teller-strokes, that mark the passing of a man."

… while the bell was rung three times to indicate that it was a child who had died, and six times for a woman, ‘telling’ the villagers by the number. So ‘tellers’ has become ‘tailors’ over time, as people have forgotten the custom.