What I'm saying is that Stuart himself arrived at Gettysburg about 2:00 PM. He then reported to Lee. Two of the three brigades that had been with him on his expedition began filtering in an hour or two behind, and those two brigades were in Gettysburg by about 5:00 PM on July 2. The third brigade--Hampton's--fought the battle of Hunterstown about 5:00 that afternoon and then completed the march to Gettysburg. They arrived sometime after 6:00--the precise time is not known.
Here's what you need to understand: fully half of the Army of the Potomac's Cavalry Corps--four of the eight brigades--were operating either on Lee's left flank (Gregg, with two of his three brigades at Brinkerhoff's Ridge) or beyond it, at Hunterstown (Kilpatrick's two brigades), late on the afternoon of July 2. That is the very specific reason why Lee sent Stuart out there on July 3--to prevent those four brigades from getting around his flank and into his rear. It's also the reason why Lee summoned John D. Imboden's brigade to come to the battlefield and to take position behind the center of his line so that there would be a mounted force available to defend if that Union cavalry did get around the flank and into the rear. Stuart, with about 4100 of his best veteran troopers, was sent there to guard Lee's vulnerable flank and to make some mischief if the opportunity presented itself.
Make no mistake about it: Stuart's primary role on July 3 was to protect Lee's left flank from the large force of Union cavalry that had been operating there on the afternoon of July 2. Gregg's two brigades and ultimately Custer's brigade of Kilpatrick's division had the same assignment: guarding the Union flank. Protecting the flanks was the traditional role of cavalry in the Napoleonic model, and both sides were using their cavalry in that classic Napoleonic fashion. The Federal horsemen had no orders to try to get into Lee's rear, but Lee had absolutely no way to know that. Sending Stuart and his cavalry to guard his flank is exactly what cavalry is supposed to do, and Stuart did so quite effectively. That he almost broke through to get into the Union rear was just a benefit. It also explains why he only made a single attempt at breaking through the Union line at the end of the fighting on East Cavalry Field.
You should also be aware that Lee had Jenkins' brigade with him on the battlefield on July 1 and July 2, although Jenkins was wounded on July 2 and due to a breakdown in the chain of command, his men were left without orders for the rest of the day. There are no surviving accounts, so we don't know what those men did, although we do know that they didn't participate in the Confederate attacks that day. Again, that is in no way Stuart's fault.
Lee only summoned Imboden's command to the battlefield on the morning of July 3--a choice made by Lee himself. And had Beverly Robertson obeyed Stuart's orders instead of dawdling and not arriving until the morning of July 3, Lee would have had two brigades of cavalry with him when he marched east from Chambersburg on July 1. That Robertson was relieved of command and never commanded troops in the ANV after the Gettysburg Campaign speaks volumes--Stuart got rid of him, this time for good. It is hardly Stuart's fault that Robertson disobeyed his orders. There is, perhaps, some culpability for Stuart in not leaving Hampton's brigade and taking Robertson with him, but Stuart despised Robertson and didn't want anything to do with him. Even Jones would have done a MUCH better job, but Robertson outranked Jones by virtue of seniority. Jones excelled at that sort of duty, but in an army that relied on seniority, Robertson ended up in command of that detachment, and it cost Lee the cavalry escort that Stuart had carefully planned for him to have.