I agree, it would be nice if this bug were fixed. However, it doesn't happen all that often.
The bot does usually put Fungals between two minions. However, sometimes it does put Fungal to the side.
I believe the bot only considers what it can do in the current turn when evaluating its moves. If you have no minions who can attack this turn (or only one), then buffing two minions makes no difference this turn, since you wouldn't do any additional damage. The bot doesn't seem to care if a minion gains additional health.
It would be nice if this bug were addressed one way or another. The general strategy used by this bot (only consider the current turn) causes various misplays like these, unfortunately.