Apparently there's no possibility to re-arrange the shortcuts list of My Portal.

Here's a trick: Add a sequence number in front of the name.

Example
- before
AAA, Personal
AAA, Global
DDD, Global
NNN, Personal
ZZZ, Global

- after
1. ZZZ, Global
2. NNN, Personal
3. AAA, Global
4. AAA, Personal
5. DDD, Global