Well actually!... No, sorry couldn't help myself. You left that one well open for that joke
(Just to be clear I'm not the one you replied to there, I just thought I'd chime in again - I'm the guy who originally answered your question about Voice Control's ability to perhaps replace Dragon dictation for you)
Anyways, chiming in again;
Despite being maintained by Apple in Cali, Siri works way better in Spanish actually, because the language is way more phonetically consistent, thus lending itself better to computer speech-to-text software. Though when it comes to English accents you should be good
I'm Danish myself though my accent is more hybrid after travelling a lot and just generally being exposed to English from many different accent-angles. - In any case, my point is that it works well for me the majority of the time, so you definitely should be good to go.