Hi there,
I would say based on limited info here that you have a good start to your profile, and I wouldn't say that adding another year or two just for the sake of '# of years' will make a big difference, UNLESS you feel you'd really make even more impact or show even more leadership during that year that will than better position your resumes, essays, and recommendations. So think on that point. But having 3 years when you apply, 4 when matriculate is while a touch lower than average, still pretty common. You may just need to stress the QUALITY of your experiences, and why NOW is the right time to apply vs waiting longer. Probably the bigger challenge is simply that there are a large # of applicants with similar strong profiles, and with the school caliber you've mentioned, it can be tough to stand out from the crowd, so HBS/Wharton will be a reach as they are for most, and the others still a challenge but your stats and basic professional profile will help you hopefully get some interviews if you do a great job on your apps, and then go from there. Good luck!