I do stuff and thingies... Try widening and reducing the number of small nooks and crannies to correct the problem.
STARCRAFT II: HotS - Balance Update #14
--- HOTS beta balance ---
Quote from Blizzard Entertainment
Terran
- Hellbat
- The cargo space required to transport a Hellbat has been increased from 2 to 4.
Source
But not the hellion?
I mean unless I'm mistaken could you not just transport hellions and then transform them if they have such efficacy?
"If a topic that clearly interest noone needs to be closed to underline the "we don't want this here" message, is up to debate."
-NudeRaider
They take around the same time to transform as an unupgraded Widow Mine takes to burrow, if memory serves.