Check the scaling and position (coordinate system) of your original CAD models. Vuforia will use that information to display the models, so, for example, if your CAD model is positioned at (100,100,0), then Vuforia will position it in that location.
There are ways to fix this in Creo Illustrate, but it can be tricky with complex assemblies. Maybe the engineers on here have suggestions for easy ways to adjust the coordinate system of a model--I've definitely struggled with it for certain models.
It might be easiest to have a set of values that adjusts the position and location of each model when it is dynamically loaded. For each model, find the location and scale that works best, and when you load the model, set those values on the widget to position and scale it correctly.