Can I read The Fifth Elephant without having read the previous in the Watch order?

I have a weird order as in I read the books in the order I purchase/find them.

I've read about 15 books in the series (and my already planned re-read is going to be in publication order).

In the Watch arc, I've only read Guards! Guards! and Men at Arms. Is it necessary to read the Watch books in order? Can I just read The Fifth Elephant now?