Scourge is actually the very next book I have to get to. I have it as right after Vision of the Future (I have about 100 pages left) with the Union Dark Horse comic after Scourge. There isn't much activity going on in this area where there can be lots of questions on story order.
as I go. I believe everything listed is in order of the date it was published as occurring at, but as things went on and The Clone Wars TV show came to be, that required shifting around some things to fit better content wise. That's the type of thing that you have to juggle yourself when you approach a group of stories that are dated one way but content wise would make more sense in a different order. There are stories that can't be 'fixed' and you have to accept those hiccups, but there are also stories that by simply ignoring the intended date still work in the overall scheme when placed in a different order.
Also, there are stories that don't have overlapping events or characters, and you can jockey them around a bit if they aren't extremely specific. We simply have no info as to whether this group of people was doing their thing before, during, or after what another group of people were doing. I don't remember much of the details of Scourge, but with the Hand of Thrawn duology, Union, and Scourge all being at 19 ABY, Union must follow the duology, you would probably want to read the duology back to back, so that leaves Scourge to either go before the duology, between it and Union, or after Union. And this is the kinda thing you have to figure out when you get there. I'll also refer to Wookieepedia to get a quick view of the details, or The Essential Reader's Companion, because a simple detail may help place a story better. I mainly combine those two lists as my main source and don't specifically follow the Essential Companion as my main order (it doesn't cover comics anyway).