From my understanding most of these regiments were comprised of single battalions, while at the same time they continued to maintain HS capabilities as if they were regiments. In essence the British army was over supporting 5 infantry battalions by individually giving each battalion the support that would normally go to a regiment.

To me it would make sense to combine these battalions and which would reduce the total administrative support required required to support all five individually. I understand the role history plays in this, but it seems that each battalion will be able to maintain it's own identity and in any case Armies have always evolved; Regiments have been stood up and disbanded, combined together etc.