ECT1 job offer is mostly KS3 (teaching)

Hi everyone, I’m currently training as a History teacher (PGCE) and have two job offers. I’ll lay it out below but my general question is, is teaching mostly/only KS3 going to be detrimental to my career? I’d like to do a couple years in the UK then try get an international school job. Anyone been given any advice or know anything?…
1) Teaching KS3, GCSE and 2 A-levels (History and Politics). It’s a more demanding timetable which makes me feel anxious/overwhelmed, in a school with a reputation for a toxic management, but lots of structure and shared resources for a new teacher.
2) Teaching only KS3 and potentially a year 12 class in first year. Probably GCSE then added in year 2. But overall a KS3 heavy timetable and potential for other bits and bobs like citizenship to make up the hours. Less demanding and school 2 has a reputation for being laid-back with lots of teacher autonomy, but less structured and organised for a new teacher, and lacking shared resources.
To summarise, school 1 might break me and I worry I’d quit teaching if it proved too much. But would School 2’s offer of mostly teaching ages 11-14 at first limit my future prospects and employability, particularly in the international market? Is taking mostly KS3 a risk or something to be avoided as an ECT? Any thoughts on any of this welcome!

Neither looks ideal to me.
We'd normally give a mix - some KS3, a Year 10 and a Year 12 class. We tend not to give Year 11 or 13 to someone new

I agree neither are perfect tbh. Not sure what to do!

Are these your only options? They'll be lots of jobs next term when experienced teachers can't apply because they can't resign after the end of May.

It’s a bit complicated, these are my two placements that I’ve been on and are both some of the best schools in the area, so I wouldn’t really want to look elsewhere. Also, I have already agreed to the job for school 1, but since being at school 2 on placement I have heard of the toxic reputation and been advised to tread carefully there as the school tends to crush people… I know it’s complicated and quite stressful trying to weigh it up, as I worry I’d quit teaching altogether due to school 1 pressure, but worry my career/progression might stagnate in school 2! Sorry for the info dump.