User @theoretical has done some mathematical calculus about curation rewards in his 6 blogs. They are kinda hard to understand and pictures disappeared from his blogs. Serch option for you query on steemit does provide some useful links.
To answer you question in words as how do I understand it. The answer is yes, everything is calculated your position when you voted. If u are 1 to vote than you would get more than you were 2 to vote. Your SP and voting power also matter. According to those elements you are later, say after 100 votes placed on a list where position shows your position in payout line. When you look at the list who voted on a certain post, users that are listed there are sorted in a way that shows their curation rewards row.
The factor of time that you mentioned in your blog post and a number of voters before you along with you current SP and voting power all affect your payout. So the ideal time to vote on every post varies. Most famous bot now votes after 8 minutes to maximize his reward and he gets a big part of rewards with only 40% of voting power. For us small users this is bad news since he with so small power has more power than 95% users on the platform.
The amount of SD is connected to available rewards per hour as far as I know but does affect available curation payout of a post since users with higher SP voted and gave post more $ so they have taken an earlier cue in curation rewards .