You might want to bump up their occurrence a little as well: you tend to either get 3-5 of them in a game, often in the same system, or absolutely none.

I expected this to be about multiple stations in a system (of types with randomly selected names) having the same name.

I've fixed this in 1.6 Beta 6 so there is never more than 1 Tinker per system. Also, I've added a minimum so there is always at least 1 Tinker in the game.