Complex sentence: UK, USA and Australia all had their own domestic series and sent recent champion contenders and selected gladiators, while the other three countries did not have their own shows at the time although this was not indicated at the time of filming.
Split into simpler sentences: UK, USA and Australia all had their own domestic series and sent recent champion contenders and selected gladiators. The other three countries did not have their own shows at the time although this was not indicated at the time of filming.