As far as I know it depends on the model and weight! A lite weight trailer will have the A frame all one hieght. The heavier trailers got the dropped A frame. My old Cherokee lite had the continuous frame with he A frame all one hieght, but it had wheel wells and an elevated slide. My current Cherokee has the raised frame with no wheel wells and a flush floor slide. It all depends on how it's built.
But there is nothing to worry about with your current A frame. Mine has been solid for well over 10k miles. There were some frames years ago that the manuf spec'd a thinner wall box tube, those were failing pretty quickly. The new ones shouldn't have that issue.
