Eh, mostly just that the OP wanted to play with hulangs specifically, so I jotted the list down to use two of them. If one gets ganked in round 1, he can still play with hulangs like he wants. Sure, one yan huo would probably be fine. I took two for redundancy and coverage. The yan huos could be deployed up to 16" apart with different lines of fire around some intervening building so that it's harder to hide from them while still blocking the hulangs' advance. The doc and yaozao could be nearby to get them up if they're shot down. The link team mostly hunkers down and makes it difficult to outflank the yan huos with airborne troops or skirmishers, but can also do some late game objective grabbing.