No expert on this, BUT
Did the Scots not abandon their hilltop defense because :-
1) They could not depress the elevation of their artillery (superior in firepower and numbers) to bear on the English below, and 2), The English artillery were making free targets of the Scots who could not answer unless by actually engaging in H to H combat.
3) I believe the Scots were using Pikes (Capt.of Dragoons), albeit, not in Schiltrom formation, the trouble was, The English had moved on technically, and using bills, they snared the head of the pikes and snapped them, rendering them useless.
4) The press of men behind, eager to join the affray from above and behind on a slippery slope left little scope for dis-engagement of the front ranks.
The rest is history, the best equipped, most homogeneous (Lowland and Highland, Lords and commoners alike) army to set forth under the most loved (James IV) King of Scots came to a very, very sad end at the foot of Branxton Hill.
Neil Oliver (Two men in a Trench (and Coast) did a very good historical documentary on this, and Killiecrankie, Bannockburn and Culloden amongst others.
I obviously watch too much of the wrong kind of television when painting figures
Not my period at all, (too sad)
but my understanding of what happened. I am sure there are more qualified than I to comment, and would look forward to this if it is forthcoming.
"There is no retreat from here, men," Campbell told them as he rode down the line, "you must die where you stand."