The question of how big a club is, is an interesting one. Traditionally it was based on size of attendance. Hence our porcine neighbours still classify themselves as a big club.
The reality for most EPL clubs (and therefore bigger clubs by league position), is that most income is generated outside of attendance money, it is gained from TV, sponsorship, commercial income and player sales.
So Brentford, Brighton, Bournemouth, Palace etc use this model to stay in the EPL.
For most teams, it's not about size of attendance anymore, it's how you spend your TV money, and how you develop your players to flip them to the top 6 clubs.
We can do the same, but it will take money, and also we need to expect and deal with some failed gambles (like Brewster). We are off to a flying start with the current crop of academy lads, but we will need to sell them at some point to stay in the EPL (assuming we get there), and to get the right price for them. Bournemouth, Palace, Brighton, Brentford do this all the time, and Southampton also did it for years.