The window is large enough for 2 attacks, so as long as your not button mashing, you should have time to execute 2
If you're a little slow on getting to them on your bar, then you might only get 1 off, but it's still good

Macros are always going to be slower than a player, due to delays in running the macro, server lag and tick timing
(wait 1 can be shorter or longer depending on where the server is between ticks)