Every design is a compromise. I expect 3200s weigh less than 5200s so that means you get more cargo capacity within the GVWR. Some include water and propane in that CC leaving less for your camping things.
Rant warning--
The other big deal is the 10,000 lb limit for a special driver's licence. You see lots of trailers with GVWR at 9,900 lbs.
That is a total farce though. Our 2003 has a pair of 5200s and GVWR just under the limit in BC (in kilos) for a special licence. It came with C tires. A couple years later, the company switched to D tires on the same dry weight trailer, and jacked the GVWR up to 11something lbs.
So I would need a special licence to pull my same trailer just because they put Ds instead of Cs on them. As it is I got Ds and am still legal because the GVWR on my trailer stays the same. What a farce.
Then they invent a way to assign the GVWR by adding the dry pin weight to the GAWR or whatever, which is silly, because you don't drive with the dry weight, you have a loaded weight. Another farce.
You really have to load up and go the scales and get real numbers. Then you have to read your law about whether they count the pin weight in their limit for the driver's licence. Some do and some don't (giving you more you can tow)
Don't forget individual weights on each tire either. The scales do all at once or two tires at a time , but you can be heavier on one side and back vs front axle, so one tire can be taking more than it is rated for if you are not measuring that way.
Generally, I would trust they got the strength of the frame and tongue and axles right for the GVWR they give it, and pay more attention to your tires, which is the real "weak link" in the whole thing. Especially if you go more than the rated speed limit on your trailer tires so they heat up. Gee Ma, my crappy tires just exploded--it must be those cheap tires from Country X, and not because I was speeding! :(
Rant ends.