[CQ-Contest] Can a call be too short?

[John Geiger]

I am helping with some research about ideal calls in terms of DXing and contesting, and was rereading some of the old posts about ideal letters in a callsign. I wonder if some combinations can be too short for CW?  Do the single character letters like E and T tend to get lost in pileups and require repeats a lot?  Would a suffix like EET or TET be problematic?  Or does it help that they are shorter to send?

73s John AA5JG