Is it possible to apportion server resources?

Sorry, this may be a dumb question as I’m new to Cloudways setup.

I have a couple of different Wordpress sites I manage. Some get hardly any big traffic, others are more intensive. Is it possible to ‘prioritise’ some sites/apps over others on the server? So for example, Sites A and B always get 80% of server resources, Sites C and D only 20%?

Or is the only way to achieve this to have high-traffic sites on higher plans and the less-visited sites on a different, basic plan?