How many European countries can you realistically visit in 2 weeks?

Hello, I’m from Orlando Florida. I have 2 route ideas and I’m not sure if it’s too much or even realistic.

First plan was to fly into London, and make my way to Amsterdam. I think I’m not being realistic but flights into the UK are significantly cheaper.

London Paris Brussels Amsterdam

I really want to do an entire UK trip over 2 weeks because the culture has always interested me, especially wales for some reason. Can Cardiff be a day trip from London? My husband doesn’t have any interest in visiting the UK much.

The other plan is flying into Lisbon, and making my way to Brussels

Lisbon Madrid Paris Brussels

We’d likely be traveling by train or plane, whatever is faster and cheaper.

Should I be cutting one of these cities out of my itinerary?