hasta does mean spear, but there are many names for spears, throwing or thrusting, that were indistinguishably used by Latin authors to generally describe a spear (once again, throwing or thrusting). My point is that it's impossible to make a conclusion on the use of their spears when given such a generic name for this class of pole-arm, without given further context. Many primary sources record the
hastati throwing
hasta, throwing a storm of steel, etc.
gladius is a generic name for sword. The
gladius hispaniensis was encountered before the 2nd Punic War. The early Roman swords were like Hellenic swords (
xyston, specifically), but not identical, and shouldn't be called Hellenic.
Again, these early warriors were described with
hasta, and
hastae have previously been described as throwing weapons. It's not correct to assume that early Roman warriors of the "Servian Army" (the term you use) solely used thrusting spears, especially when considering that the native Italic fighting style was with javelins and
scuta. Dionysios also says the Principes held their spears with 2 hands... so what sense can be made of this statement?
Sources?

Both Livy and Polybios, describing the army of the early 4th C BCE and early 2nd C BCE respectively, say the heavy infantry (
hastati, principes and
triarii) were divided by age. The light infantry (
leves or
velites) and cavalry (
equites) are the only mentioned being separated by wealth, as the poorest and the aristocrats respectively.
No scholar, or author, has ever argued that
triarii were still armed with
clipei during the war with Pyrrhos, or that they retained this shield when the
hastati and
principes adopted the
scutum. What gives you (or the designer of these units) the thought that they did, and that they'd still fight in a phalanx when the rest of the army (vast, vast majority) used manipular tactics?