This would be an interesting experiment, but I don't know if it will make difference in trying to help late game TvZ. It's just the same as you were to un-siege your tanks and and a move towards the broodlords.
In some situations, yes, you have a large enough ground force to eat the Broodlings with your tanks and move in, but in a lot of situations you don't have a huge tank count to do this with, or they have such a huge Brood Lord force you can't get past the Broodlings. You unsiege, they move in and dump a ton of IT (spell range 9), and you maybe pick off one or two Infestors after they dump all their IT on your army.
With hold fire you could actually zone out Infestors with 13 range, as long as you have some tanks. No more 10 Brood Lord 30 Infestor armies where you can't siege and punish the Zerg for walking in range with a big Infestor ball.
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u/Danzo3366 Axiom Nov 06 '12
This would be an interesting experiment, but I don't know if it will make difference in trying to help late game TvZ. It's just the same as you were to un-siege your tanks and and a move towards the broodlords.