Fsmash doesn't work on heavies, where Dtilt works on everyone. Though I think using Dtilt after a Dthrow is a huge waste. Why would you do that for 6% damage when you can go for the hardest punishes you can think of? Just Uthrow them and uair them or nair them and you get twice the damage much easier.
Dthrow -> Dash attack is much better than Dtilt always.
Dthrow -> Dash attack is much better than Dtilt always.