Capt Sensational,
I guess if you have many tasks then having many small units is one response. I would favour, I think, having a few really powerful units and then some "economy of force" units that get the holding actions.
I'm going to ramble a little bit.
I've been with two "plug and play" battlegroups/task forces. While people did miss the "one battalion" sourcing, the big things they (well, I) missed were the things that used to be integral. The CSS company being, perhaps, the biggest one. I was in a company with platoons/troops from all elements and about 10 units. That never bothered me as much as not having a Sqn echelon.
It would be nice to have a battle group formed permanently, I suppose, but over a year of pre-deployment training I think that we can get past sub-units coming from different units. What is much harder to overcome is over-centralized C2 and CSS structures in theatre. This next bit might seem at odds with my first line, but a BG HQ that comes together like a train wreck is a bigger problem, in my opinion, than having sub-units from other arms join a battle group.
A unit that doesn't have its own reconnaissance assets, its own fire support and its own CSS will always be beholden to others.
I would suggest, in order of priority, the following:
a. make companies full-strength to include A1 echelons
b. have a CSS company integral to a Bn and do NOT take it away when they go to war
c. have a BG HQ that includes the core Coordination Centres (this will be expensive)
e. have four rifle companies
f. bring back the missing combat support platoons once you have the people and have done the other bits
I am sure that many would move my last priority up, and I may well have that one wrong. The BG HQ could get out of control and I might have to cut back a little, but the core centres should be there.
Having a recce sqn, an engineer sqn or an artillery battery permanently attached to the battalion would not, I believe, achieve as much as the first six.
With six of these real battalions the government could keep one in the field while still giving guys a break when they get back. The other arms may or may not be attached to these battalions when they deploy depending on the mission. Some of the other arms might attach elements to a higher level HQ. If a second front opens then we face some heartache, and that is a major shortcoming.