How can I rename files on import with counter across automatically split projects?

I would greatly appreciate any enlightment on any aspect of the following issue and details, even if it doesn't directly solve my problem, including other strategies for renaming versions.

On import, what I want to happen is...

• Versions get named with just a 4-digit number sequentially beginning with 1 more than the highest version number in the library.
• Each day's shooting goes into a separate project.

My problem

• I created a Rename Files preset that contains just a counter
• Before each import I manually set the counter appropriately (since I can't figure out how to do this automatically, although I am writing an AppleScript that does things the way I want)
• As each split project is created version number restarts at the manually set counter number rather than 1 more than the version number of the last image of the previously split project. (I am assuming -- and hoping -- that images will always get imported in date order.)

Background

• I have given up on "continuous numbering" on my Canon camera memory cards (2 cameras, 2 cards each), due to confusion occurring when I switch cards without erasing the new one.
• I decided to just number all my versions sequentially, regardless of file name.
• I don't want the pointless "IMG_" and "MVI_" prefixes to appear in my Aperture version names. [This was my original goal -- control over sequential numbering to make version numbers independent of file names came later.)

My settings

• Aperture Library
  • Destination: New Project
  • Automatically split projects checked
• Rename Files

  Version name: Counter (a preset I added with just a counter and # of digits 4; before each import, I edit the "Incrementing counter start at" value)

• Actions

  AppleScript that renames each split project based on the date of its first photo (see my script at https://discussions.apple.com/thread/2701259)

[Note: Aperture doesn't always split projects by date correctly; maybe I am misunderstanding what it is supposed to do, but I sometimes get some or all photos from one day's shooting in the project of the previous day's photos. I don't think this problem is caused by my script, because I believe I used to encounter it even before I wrote the script.]