After totting a few numbers up from the data provided in the sources linked here, I've found something that doesn't surprise me in the slightest - the values provided in Grand Survey make no sense at all.
For starters, if you look at the mass and diameter and density provided, they don't agree with eachother - if you assume two are as stated, you can't get the third value. So someone did their maths wrong when compiling that data for Grand Survey.
The other howler is that if you take the orbital period of Regina shown there then you can determine the mass of Assiniboia (you also need to know the orbital radius, but that's provided in the CT data as 55 radii, and we'll assume that Assiniboia's radius is 80,000 km which is as big as a gas giant or brown dwarf can actually be)... but when you do the calculation it turns out that the maximum mass that the gas giant can have is only 0.1388 Jupiters, which is just under half that of Saturn! That also means that the gas giant's density is utterly impossible - a mere 123 kg/m3, far lower than possible for a gas giant of that (or any) size.
So even the paltry data we have makes no sense at all!