As a long time shopper of the Target clearance, my experience
Clearances are universal: Things flagged for clearance will show up generally at the same time at all stores. However, the rate (discount) does seem to vary store by store. At store 1, it may be 30%, while at store 2 it starts out at 50%. In a few weeks, one store might have dropped it to 70% off while another store is standing pat at 30%. So the clearance is universal, but the results vary. It used to be (when Target clearances were more abundant and regular) that these hit Monday AM...you would see team members scanning stuff and if the computer flagged it, they would put the clearance stickers on them. So it could be that the minor variation is due to actual employee behavior, e.g. one week they did not re-scan stuff so it does not get the mark-down that another store has.
This is not to be confused with one-off clearances you find from time to time. Usually these are open/repack or returned online only items and are totally YMMV. The Tags, although still orange, are different than regular clearance tags.
Price drops are a mixed bag: I think there is a difference between a "price drop" and a "temporary price drop". If it is a "price drop" that is typically at all stores.. But you will see "temporary price drops" (with a sign noting such) that does seem to be store to store. I don't know if this is an inventory management thing or what, e.g. store 1 has 20 copies and so they temporarily drop the price to get down to an acceptable level while store 2 only has 5 copies so they will not do a temporary price drop.
There is some centralization/standardization at Target in terms of pricing. In contrast, I think Wal-Mart it is strictly up to each store manager at each store, so you never know what to expect. Some stores you can walk in and find relatively new releases in the bargain bin for $10, and you walk into another store and they still have copies of NBA 2K04 PS2 games and they are wanting $30 for them (which is a real example near me).
At any rate, Target clearances (on games and other stuff) is not like it used to be. A lot less frequent and less aggressive, and the max now seems to be 85%, but you will rarely see things lower than 50% off. 5-6 years ago not uncommon to regularly see pretty new releases move to 50% right away and then go to 75% in a week and on rare occasions you could score the 90% off stuff.