yes i agree with you this is not the exact order i do it these are my end result items i usually go with the catalyst before finishing my boots all depending on who i am versing see every one of these items I get in different orders every game(of course keeping the main ones in line) depending on who i am versing. almost always i get a mana or health crystal as my 2nd item or shoes. and as i said it all depends i improvise every game but these are the basics

There are a few issues that I see on this Fiddlesticks build. You are building into Tier 2 boots directly after your Doran's Ring, which is the first thing. Now, while those are incredibly useful, you really need more survivability and power early on in order to make it through impending skirmishes. If you are intent on building Rod of Ages, you should probably go Doran's Ring > Boots of Speed > Catalyst > Rod of Ages. The sooner you get that Rod of Ages, the sooner you start benefiting from its "build over time" abilities.

Zhonya's is also more of an endgame item. If you are going to build Void staff, you should build it before Zhonya's. In fact, you should probably end with Zonya's entirely, and build Rylai's before that. Rylai's will make your abilities far more effective in teamfights and ganks because of the slow.