Why British land power depends on deployable formations

Should Britain invest in more tanks after the lessons of Ukraine?

Yes only as part of a defined expeditionary force, with formations, sustainment, and amphibious lift able to move heavy equipment into theatre.

The answer starts by asking what the British Army is for and where it can realistically operate. A sustainable forward brigade may require several formations at home for rotation, reinforcement, and defence. Heavy equipment then creates a transport problem that cannot be solved by flying laden aircraft into modern surface-to-air missile coverage. Retaining amphibious ships gives the Army a route for deploying substantial equipment, so the Army itself has a stake in preserving Royal Navy lift capacity.