Altara provides casuals to both Jetstar and Tiger Airways with recruits having no say who they're contracted to. My understanding.
Perhaps the training is the same, but the mentality of an 18 year old (eg) who knows they're going to move jobs before to see his/her first EP renewal makes them a little slack to worry about safety or bother to keep it fresh in their minds?
And yes, if a company is desparate to get numbers they will pass trainees with an extra needed mark here and there. Seen it first hand happen in my initials (not in my current airline though).