Pretty good as you can get the visa? These days you see Filipinos who've only ever lived in the Philippines (and speak Filipino English with what I'd call zero tone/intonation, shit grammar and a mixture of Filo words) getting gigs so I'd think you'd come ahead of them for sure.

The bloke across the road from me in Australia is from a Sri Lankan background (born there) and has an accent. However, he's worked in Australia for 30+ years (senior IT roles most recently) and was keen to teach in Japan before going into full-time retirement. I gave him a few leads and he got a job, which he enjoyed.

IMO the only challenge is that I see ALT/eikaiwa work as being a 'gap year' where they want compliant youngsters. Some older people I know reach a stage where they are REALLY stubborn and wanna argue every little point. IMO the job's easier if you're the kinda person who's happy to just take instructions and do what your employer wants.