The wild cheering for the Romans is historical. I refer you to this quote form Polybius.Historically accurate Roman legionary animations (fs_s1_gladius):
- no wild cheering for Romans during startup
- proper relaxed standing animations
- during a fight, holding the shield close and the gladius ready next to it
- stabbing fighting style with the gladius, no slashing
Polybius, The Histories, Book XV, Section 12.8 (Online at LacusCurtius) The Battle of Zama (202 BC)When the phalanxes were close to each other, Romans fell upon their foes, raising their war-cry and clashing their shields with their spears as is their practice,
At least some slashing is also historical. Polybius clearly says they used there swords for both cutting and thrusting.
Polybius, The Histories, Book XVIII, Section 30.5 (Online at LacusCurtius) The Battle of Cynoscephalae (197 BC)Such being in general and in detail the disposition of the phalanx, I have now, for purposes of comparison, to speak of the peculiarities of the Roman equipment and system of formation and the points of difference in both. Now in the case of the Romans also each soldier with his arms occupies a space of three feet in breadth, but as in their mode of fighting each man must move separately, as he has to cover his person with his long shield, turning to meet each expected blow, and as he uses his sword both for cutting and thrusting it is obvious that a looser order is required, and each man must be at a distance of at least three feet from the man next him in the same rank and those in front of and behind him, if they are to be of proper use.