It's pretty cut and dry, Graham. Neither your "opinion" or mine, matters much. Uesbiba knew what he was talking about and it is matched in the other arts he considered. Happo giri is external and is in koratee as well as a host of arts that have not one thing to do with aiki.
Who's talking Aiki? I'm talking AIKIDO.
I will never use such terminology as internal and external. I find it limited.
You stick to your AIKI and I'll stick to my Aikido.
I watched a short video explaining aiki only yesterday. Never seen that one before. As with many martial arts I find them interesting in their own way. Not my way though. So enjoy and do well in your way. All this significance is boring.