I still have issues, however. If I do Parataikene again - and I will - I'll end up with the same off-kilter result. The same applies to other Successor battles we have had a go at, as some troop types aren't doing what they're supposed to.
So, after some thinking, this is my list of amendments that I'll be using going forward:
BASIC IMPETUS - Parataikene Amendments
CL Shooting: CL shoot with all dice in all directions, and do not suffer a deduction for moving.
Elephants: Represent elephants with two elephant models and two skirmishers bases. Modify factors to VBU 4, I 5. Elephants deny Impetus to Mounted Troops WHICH MAY NOT CHARGE THEM, and keep Impetus bonus even when not fresh. Pike Armed troops that are fresh receive Impetus against Elephants. Elephants still do not get Impetus against S & non-Impetuous FL troops
Evading: CL & S may evade, regardless of the direction of charge threat.
Offset Rule: Units may line up precisely in melee, and do not have to be side-shifted to create offset melees.
Melee Break-off: Faster units may break off from melee combat by making a full move to the rear, facing the enemy in accordance with rule 5.3. The unit becomes Disordered. If it is already Disordered it may still break off, and does not suffer the effects of further Disorder. For the purposes of this amendment “S” move faster than “FL” who move faster than “FP”.
Interpenetration: Units may not be forced to move forward or backwards as a result of being interpenetrated. The interpenetrating unit moves the required extra distance to clear the back or front of the interpenetrated unit. Any unit that has to exceed its movement allowance takes Disorder and may not shoot before or after movement.
Wheeling: CL, S & FL units may wheel and move without receiving Disorder.
About face: CL, S & FL units may About Face and move a full move as long as they do not enter combat. This may include a single wheel. All other units may About Face and move at half speed, rounded up. Again they may not enter combat.
Infantry Movement Speeds: FL move at 2H+1H, the +1H having the same restrictions as the Skirmisher +2H.
For other "Classical" period battles I'll need some more changes. For example, modifications are needed for Scythe Chariots, and I haven't looked at the rules for normal chariots at all.