Eva - to attempt to answer your last question directly, why are residents groups not spoken with before a consultant or any other decision is taken by a landlord?
Firstly, HAs and RSLs have managers whose role is to manage. Their decisions are scrutinised and monitored by adequate regulation in the main.
Secondly, if they had a responsibility to consult with resident groups over every decision, they would be a commune not a social business. The costs of doing this would be astronomical and tenants would have to pay much higher rents to cover such costs.
Thirdly, and specifically a repairs service is likely to be contracted out these days and because of its value it will need to tendered under EU regulations. So, contracts for them come up for review every few years or so and this could be the reasons why consultants have been engaged, to advise on on the tendering process or it meets legal requirements (or many other reasons).
Of course thats speculation and they could be engaged for a number of reasons. Yet it also shows that consultants being engaged on a repairs issue need not be a reason for worry for tenants. It may well be reason to worry as well, but as i stated above HAs are fairly closely regulated on practices and spending. And if the potential impact on any proposed change is a change of management practice, then tenants and resident groups would be consulted and need to be.