Can someone help me make sense of this...

Two of the three places I share my themes have a master description which I add the individual device theme files too. So this makes it a little confusing for me because I typically have one theme for four devices, each of which has a different amount of COD files that of course translates into different download sizes. For instance;

Theme X for 85xx OS5 has 9 COD files, 93xx OS6 has 9 COD files, 96xx OS5 has 15 COD files, and 96xx OS6 has 13 COD files.

So I am wondering, when one theme shares it's description across multiple devices and OS's, how do I go about determining whether or not the theme has a "Small File Size" or not? Does it go by how many COD files there are? Or actual size when downloaded (this I do not know unless I download the actual theme, which isn't an option for all versions)?

But if someone could explain a rule of thumb to follow for determining this I would really appreciate it

Thanks in advance to those who reply!