Should I risk City B70F for Diagnostic Radiography or keep my LSBU offer?

I’m really confused and need to decide today, so I’d appreciate any advice.
My goal is Diagnostic Radiography — I don’t want to do Therapeutic Radiography.
I currently have an offer from LSBU for Therapeutic Radiography with Foundation Year (B82F). I originally thought I could do the foundation year and switch to Diagnostic, but LSBU currently isn’t accepting course changes into Diagnostic.
I also have an offer from City St George’s for B70F Introduction to Health Sciences through Clearing. B70F doesn’t currently have a direct Diagnostic Radiography progression route.
My ideal plan would be:
City B70F → ask City early in the year if I can switch/progress into Diagnostic → if not, finish B70F → apply for Diagnostic Radiography at LSBU/elsewhere for 2027.
I called LSBU Clearing and they said that completing B70F with a strong grade could make me eligible to apply for Diagnostic Radiography, but they also told me not to give up my existing Therapeutic offer.
So I’m torn. City is honestly the option I want, because I don’t want to commit to Therapeutic Radiography. I’m just scared that I’ll give up LSBU, complete B70F, and then not be able to get onto Diagnostic anywhere.
Would you take the risk with City or keep the LSBU offer as a safety net?
I only have a few hours to decide, so any advice would be really appreciated.