Partially true. Toussaint is a legit 6'+ though, making him closer to Ahron in size than Tyler. Tyler Ulis is 5'8.75 and never listed over 5'10. Ahron is 6'2, almost a full half a foot taller than his brother (dunks like it too, there are highlights of him throwing down oops during actual games).
I also think Toussaint is more of a bulldog than either Ulis though. The Ulis bros strike me as more finesse players. The quickness of Toussaint and Tyler is more comparable at this point, but I think the verdict is still out on Ahron as he continues to improve and gain more of the silky smooth game his brother has. However, I think Toussaint will hold down the fort next season at the very least as he'll know the system better and has already flashed his high potential.