Through considering all the information “in the round” I’ve reached the following conclusions.
First, what the British forces succeed in doing throughout events on the 12th and 13th April is to complete one of the most difficult types of manoeuvre that an army can be called upon to attempt; an orderly fighting withdrawl whilst still in contact with the enemy.
Second, the important significance of successfully containing the massive German assault launched by six German Divisions at 7am on the 12th. This assault was launched against the centre of the battlefield at positions held by reduced units of the 29th, 31st and 34th Divisions. The Official History records “their principal effort being made by a fresh division, the 81st Reserve, against the 86th Brigade (of the 29thDivision)”. The consequence of this was that these British formations were in effect “blown apart”, mainly reassembled thereafter as composite units. The 29th Division in particular was badly affected; after the morning of the 12th unit diaries are quite vague about how units were made up and where they were located. It is a testament to the efficiency of the British commanders in the field that they managed to regroup and hold a cohesive line at the end of the 12th. As recounted, performing this dangerous and critical regrouping task resulted in the award of the V.C. for Lt.Colonel Forbes-Robertson of the 1st Battalion, Border Regiment (87th Brigade, 29th Division).
Third, the successful stand of the Guards Brigade at Vierhouck. In the various histories a common theme is the importance of the stand made by the 4th Guards Brigade. In the wider context, this stand was vitally important because it “fixed” and stabalized the right of the British line at a time when the centre was under severe pressure and being rolled-back as a result of the large scale 7am attack referred to above.
Fourth, saving the high ground behind Merris. Composite units mainly of the 31st Division successfully performed the vital task of holding the highest ground on the battlefield; the heights behind Merris. Colonel Gurney’s composite unit, comprising mainly 92nd and 93rd Brigade (31st Division) troops, deserve the lion’s share of the credit. In doing so they stabilized the left of the British line in this sector. If the Germans had managed to evict Colonel Gurney from Merris they would have been able to enfilade all the lower lying units (29th Division included) as far as Vieux Berquin, and probably win the battle.