In fact...Germany does sorta force other European countries to buy it's crap.
Mostly through using various EU funds and contracts Germany secured majority shares in various European defense contractors. Also using various EU market liberalization mechanisms it's defense contractors ended up buying up various local suppliers.
Germany essentially used the EU and it's predecessors to backdoor itself into a dominance in defense contracts across the countries where NATO and the EU overlaps.
The Brits made their own tanks because of the whole Euroscepticism thing, and the French made their own because for a long time they weren't in NATO. That's how Sweden ended up with its own tanks and jets too.