For a product we wear routinely and soooo close to our eyes, it makes a lot of sense to know what's inside the tube!
Basically when you break it down mascaras have five main ingredients:
By changing the percentage of each ingredient, the final product will create a different effect. Waterproof, volumizing, lengthening, etc. - regardless of what is listed as the effect, the overall ingredient label will likely be pretty similar with just different concentrations of each ingredient.
The other thing that contributes to these properties would be how dense the bristles on the applicator brush are. The more densely packed the bristles the more likely it is a volumizing product.
In terms of whether or not this contributes to the clumping still boils down to product exposure to air resulting in drying out prematurely resulting in clumping.
If the bristles are more dense, then more product can technically accumulate. However, if the product is well maintained this shouldn’t be an issue!