Royal Navy, more investment needed?

Considering the economy at this time I personally think the best way to increase the number of ships in the navy is to replace the Invincible cl light carrier with new light carriers based on hms ocean as this would avoid cost escalation. I don't think the royal navy should replace it's ballistic missile submarines because this eats up alot of money that could be used to replace more of the navy's type 42s and type 22's.