Yep, sure does.
The different sizes of spears may be hard to distinguish in this shot of one of the asparagus rows in my garden, but some spears are thin and slender, others are fat and thick.
This is a thick spear before harvesting.
Here are a few spears of the batch of asparagus I just harvested. There was a great variety of sizes and shapes, both in width and length. (The longest one shown here measured 19" long.)
These three were the fattest or thickest.
Of the spears I've harvested this year, all of them (no matter size or shape) have been tender and delicious.
Before using a spear, I start at the cut end and press a sharp knife lightly into the spear as if to cut off a piece. An inch or two (sometimes more) nearest the cut end will feel woody and tough. I progress with my knife testing up the spear until I reach a spot where the knife blade easily starts to cut into the spear and that's the point from which I start taking the cut pieces to use.
So, no, when it comes to the thickness of the spears that may grow in your garden, size does not matter.
Having said all this, I have no idea where those uniformly sized bundles of asparagus for sale in stores come from. Well, okay, they come from large, commercial asparagus patches. But what happens to the bigger or smaller stalks, the misshapen ones? Commercially prepared Cream of Asparagus soup, anyone?