The difference between the Wing T and the Veer.
Well, for starters, the Wing T pretty much blocks every defensive player at the point of attack. The Veer leaves at least one and usually two defensive players unblocked at the point of attack. These unblocked players are accounted for by the "reads" made by the QB. The player that isn't covered by those two defenders (the QB and two running backs) will get the ball if the Veer QB does his job.
Below is a diagram of a Wing T sweep as best as I can remember it. I haven't ran the Wing T in over 13-14 years. It's kind of fuzzy.
As you can see, every defensive player playside is either down blocked or picked-up with the trapping guards. Once the QB fakes to the FB and hands to the HB his only responsibility is to carry out a good boot fake.
In the Veer, the Outside Veer in this case, you can see in the diagram below that the end man on the LOS isn't blocked and neither is the CB.
As the left HB dives, the QB opens and faces out. He extends the ball straight at the DE and steps toward him. The HB, whose heels were 4 yards from the tip of the football is running for the inside foot of the tackle as fast as he possibly can. The DE must decide in a split second whether to tackle the diving HB or wait for the QB. The angles taken by the backs and the line splits dictate that he must commit to either the dive or the QB keep... but not both.
If the DE squats or even better, comes hard up the field, the QB leaves the ball for an extra split second and the dive back takes it since it is there. The ball is handed and the HB hits up the field on a track which will take him to the hash, then the numbers, and then the sideline on his way to a touchdown.
If the DE collapses hard down and into the LOS, the QB pulls the football and proceeds around the collision of the DE and HB... and then gets upfield. The CB is read now for the pitch. If the CB takes the QB, the QB will flip the ball to the trailing HB who is maintaining pitch relationship at a 5 to 1 yard ratio. If the CB stays outside to take away the pitch, then the QB tucks the ball and keeps it on his way to the Veer lane. As you can see in the diagram, all three of the backs on the 12 Veer are darkened to signify that any one of the three may end up with the football. On 929 (am I remembering that correctly, lol?), the HB is the only one darkened since it is predetermined that he will get the football.
The Veer was developed to utilize undersized but quick offensive linemen who primarily double-team or veer release to block LBs at the point of attack. Backside linemen either cut-off (scoop block) or simply cut the remaining D-linemen. The deception of the Wing T lies in the QB reversing and hiding the ball from the defense as the play develops. The deception of the fast-mesh Veer is that the plays hit so fast to either side that the Dlinemen and LBs have a hard time finding the football since the dive hits so fast north and south. And if the defense collapses down to take away the dive, it will look up to find the QB or pitch back streaking down the sideline.
I hope this helps answer your question concerning the two offenses. Thanks for the interesting question.