how likely is a job with an airline being guaranteed at the end going to be
0. Literally 0.
Even in the airline schemes it can easily be argued that there is no guarantee. They will nearly always have clauses and sub clauses that basically say if you don't match their standard, its terminated and if they don't require any pilots afterwards its terminated.
Going it alone whether modular or integrated the answer is even more 0.
That's not to say it's impossible to get a job (it's very difficult at the minute and not LIKELY to happen very soon after training) but to want a guarantee. Nope.