That head/tail thing is kind of a goofy argument. For one thing they aren’t duals; tail is naturally more complex because the end of a file often changes and the application can optionally keep showing you the new output. Also, the fact that they’re separate applications in the first place is arguably better than the a one-application approach, which would always require a command line switch to select between outputting the start or end of a file. And finally, while I guess this could vary between implementations of head and tail, mine has identical switches for all the common options.