Adobe has a sophisticated engine that balances line breaks. The ME version re-engineers this for RTL. It understands that the "end" of a line is on the left and the "beginning" is on the right. It also correctly handles numbers: If you type a Western number in an Arabic sentence, the ME version handles the bidirectional (Bidi) algorithm correctly.
Access the "Middle Eastern & South Asian Single-line" or "Every-line" composers for correct character joining and spacing. adobe illustrator middle east version