A pilot currently upgrading at RAH has no bearing on the upgrade time of a pilot starting at RAH today.

With all being equal you will need 50% of the list above you to quit. Take into account other factors at a no change airline, you may see upgrade around 55-60%. However, each % below 50% means there is approximately that % above you that will keep you from moving up the captain bidding list as they upgrade.

If you need 1000 SIC and 2500 TT to upgrade, getting hired with 1500 hours will likely take you at least 1.5-2 years after your hire date for you to reach 1000 SIC hours. You will take 3-6 months after your hire date to even get a chance at starting to average 83 block hours/month(1000 block hour/year limit). Get hired with a 1000 hour restricted ATP, and you are looking at least 2-3 years.

Getting hired at a regional that is shrinking, having problems staffing and parking planes due to it, will cause you upgrade time to be longer than if you went to a regional that was stagnate in it's fleet size and is able to staff. A regional that is truly growing after you arrive and you will see a upgrade time that is quicker than if you went to a stagnate regional. There are your projected upgrade times.