Hey Rob,

How are you measuring the performance time / resources? There is a lot of mistakes that web masters these days do which leads to more bottlenecks especially with caching. It doesn't mean that if there are more assets loaded on the site would mean the site would run slower. That is really just a myth. It all boils down on how long your initial load time takes for the initial page to load.

Thereafter, it also looks at the size of your assets files. For instance, if you have 3 css files separated from the site with the following scenario (This is just a simple rule of thumb but it doesn't mean that having 3 css files would be faster. It all again depends on what you are trying to achieve)

1. Site template
2. Component template
3. Modules template

vs

1. Single css file combined above.

The page would have a perceived value that the site takes longer to load because it needs to wait for the entire css file to be rendered on the site before being displayed on the screen.