I don;t think Sadler was lucky with injuries. The back 3 he started with, McEntee, Farquharson and Allen was very strong indeed. The only fortune is arguably that we had good players in reserve and that is not really down to luck.
I think Lowe has to play, so JG would probably have been playing the replace Jamma role that Albert has had to do, and probably made a good job of it.
And we should also give credit to the coaching staff that, when players do come in, they know their place and click in smoothly.
Finally, losing George Hall was very bad luck.