How the game currently works: if the number of aliens to spawn ends in .5, the number that spawn is rounded down.
Example: Deployment calls for 1-4 aliens. On medium difficulty setting (Veteran and Genius), it spawns 2.5 (2 after rounding) aliens.
Suggestion: round it down for Veteran, but round it up for Genius
Example: Deployment calls for 1-4 aliens. Veteran difficulty spawns 2 aliens, and Genius difficulty spawns 3 aliens.
This change would put Genius difficulty more in between Veteran and Superhuman, and would allow a savvy modder to adjust deployment numbers to increase or decrease the difference between Veteran and Genius.