If you still have TMO installed, pick any convoy layer. Say late 42, early 43 or onward.
Immediately, you should notice that the convoy route while going along the same general path is not exactly the same. Zoom in on any convoy path, and it will look something like this:
Each one of those legs, is roughly 20 to 30 KM if i remember correctly. Each circle you see at one of those waypoints, if i remember correctly, is about 10 KM.
Traffic doesnt follow the exact line, because the 10KM radius at each waypoint defines the width of that lane. It also says, "I will turn randomly at this waypoint anywhere within this 10 KM radius." So if one deduces the zig zag pattern, and thinks each leg to be a certain length, the convoy will still not shift direction at 100% perfect intervals. It may zig zag a little bit before, or after you anticipate it to, assuming one you were to track a convoy long enough to figure out roughly how long the zig zag legs were.
In each convoy entry. Click on it, right click, and i beleive the sub menu was "define group composition". Compare that with any stock version of the exact same entry and you'll find several differences.
1.) Each unit listed as 1 each. I didn't put, "4 Each of This ship". I put 4 different indvidual entries. The reason is, in SH3, sometime ships would spawn on top of each other, Or they wouldn't follow in a group correctly. I didn't take any chances and "fixed" this as I knew to do in SH3.
2.) All units are "generic". Meaning, the game will randomly spawn any ship within this class. Generic tanker, generic troop ship. Each time the group spawns, it will randomize the ship within that type. So no instances of that convoy group should have the exact same ships.
3.) You'll find some ships have ammo as a cargo, some tankers have oil or fuel. I even went as so far as to make sure that tankers heading to japan had oil/fuel. Tankers heading away from japan might not. From what i've read, Nobody seems to have figured out that northbound tankers have a much higher probably to go BOOM, then southbound tankers in TMO.
4.) Crew ratings (obviously)
5.) Number of columns, and their spacing. As i recall, default spacing is 500 meters. I made them around 700 or so. This is to fix ships from fishtailing while following the ship in front of it. Stock SH3 had this problem. Again, i didn't take any chances, and fixed this ahead of time.
6.) Some units are not 100% spawning. I intentionally lowered the spawn chances of some ships within a convoy group, to randomize the number of ships within the convoy, and/or the number of escorts i has. Idea being, along with the use of generic entries that no two convoys should be of the exact same ships and numbers of them. In theory at least.
7.) The number of escorts and the number of merchants. Stock did some stupid things like 10 escorts and 30 merchants for every convoy. This is one of the first things I addressed.
lastly, If you check the "group properties", you should notice the spawn frequency is very different then stock.