The attrition usually goes down exponentially semester by semester. You have a legit concern, but you won't keep losing 15+ ppl or 10%+ every single semester if that's what you're asking. The first semester is tough academically, but you also lose kids who realize it's just not for them... and ones who transfer to another pod school, dent school, DO school, etc. It depends on the school and the curriculum... where I went, it was actually 2nd semester that had the hardest courses which tended to get ppl flunked out or 5yr program. It sounds mean, but it actually best the schools weed out those folks early (or just never accept them??) who don't study enough or don't have the aptitude... rather than let them bumble around failing boards and spending more money in extended years of the program and likely getting no/poor residency as an end result.
When I was in pod school 10+ years ago, NY and Chi usually had largest attrition (since they'd start with accepting 100+ typically). Barry and Cali (SF only back then) and Ohio and Temple were more middle size acceptance and middle sized attrition . Ariz and DMU were lowest starting size and therefore lowest attrition (not always % but usually lowest total ppl fail to complete the program). I honestly have no idea what schools do what now in terms of how many they are allowed or choose to accept each year... or what their standards are. They can all give you what you need. Still, the more they accept, the more will flunk out, and the more selective they are in terms of MCAT/gpa/etc, then the higher the % should be that finish the program successfully. My grad class might have gone something like 60 start fall>55 spring>50 summer>47 fall>45 spring>44 summer (then no more lost after first couple years... maybe a few had to re-take boards pt1, but they got through and graduated as long as they'd made it to clinicals and start of 3rd year)
You sorta just have to play past the attrition and focus on yourself... plenty of exams and things to keep you busy. You can only control what happens to you. With those people gone, you will notice that it gets tougher and tougher in 2nd year to get high marks (since most classes are curved), but always just give your best effort and do the best with your gpa to keep all clerkship options open and board exams basically a slam dunk.
