Gerrymando – it sounds to me like your Plan is facing precisely the same conundrum that ours faced 8 years ago, where as JGOWI suggests we resolved to amend our Agency Agreement to the extent that our then Strata Managers were engaged to oversee all activities at our Plan as if they themselves were paying the bills.
Well in summary, we paid for a Rolls Royce and our Strata Managers delivered a pushbike!
There were too many problems to list here, but suffice to say that many of those were of the same types as your Plan now experiences, and additionally, we found out that we were paying a premium price to the Strata Manager’s “Preferred Contractors” to offset the payment that they themselves were required to make to the Strata Managers in order to be on that preferred list, and to account for the Strata Mangers’ inability to meet their payment terms.
In my experience, and I know I’m generalising, the quality of the training that Strata Managers receive has been compromised by the fact both their initial assessments of competency and the nature of their professional development can be delivered and assessed by Registered Training Organisations that are often industry- based, and where in too many instances everyone who pays the fee, and turns-up, passes!
Whilst I don’t think that poor training and development leads to deliberate incompetence, in my opinion it does lead to ill-prepared people being loaded-up with a large portfolio in circumstances where they simply don’t know that they don’t know (what they’re doing), and therefore don’t seek assistance from their more experienced Licensee, and lead their Clients down the proverbial garden path.
Our Plan’s path lead to self-management where our Executive Committee (and particularly it’s hard-working Secretary / Treasurer 
) DO manage it as if every dollar spent was coming out of the pockets of the individual Members, as if every plant and blade of grass was in their individual front yards, and every light was on their individual front balconies.
I’d venture to say that NO Strata Manager with a portfolio could manage a Plan as well as a committed E/C with one, so if you and your E/C wants to pull the reins as tightly as you’ve indicated, then it might as well bite the bit and manage the Plan itself on the O/C’s behalf.