Local Government Minister Carl Sargeant has attacked "complacent" councils for not sharing senior officials.
He threatened to force them to work together if they did not make progress.
But he ruled out full-scale local government reorganisations, saying it would cost too much and disrupt services.
Council leaders said they were working together and protecting frontline services from cutbacks.
Mr Sargeant said he wanted to challenge "complacency, under-performance and senseless bureaucracy".
He told the Welsh Local Government Association (WLGA) conference in Swansea on Thursday that he expected to see more collaboration and joint appointments between authorities.
The staffing structure at the 22 councils was outdated, with too many of them independently hiring chief executives over the last year without looking at other options, he said.
"We are missing opportunities not only to make savings, but more importantly, to recruit the best quality people, from within and beyond Wales, who can help us deliver an ambitious change agenda," he said.
"I am expecting much more progress in this area. If I do not see it, I will have to consider other more directive options to force the pace."
It is understood Mr Sargeant is considering legislation to make sure he can direct joint council appointments and dictate closer collaboration across council borders.
Councils could cut duplication and increase their buying power by working together, he added.
"I know there is already extensive collaboration between local authorities but there is clear scope to do more."
But WLGA chief executive Steve Thomas said: "I think the problem here is we've got a poor man's version of local government reorganisation happening.
"There's now a very strong current of thinking within local government that if a minister wants to reorganise local government he should perhaps come out and say so in the most clear possible terms.
"The problem is that he, like us, is caught between a rock and a hard place. It's a very costly thing to do, we've got elections next year and nobody's asked the public about this yet."
He added that the cost of chief executives across Wales was £4m out of a total local government budget of £5bn.
"The money is actually in services and not posts."
Opening the conference, WLGA presiding officer Meryl Gravell said: "We can all be proud at the way in which local authorities in Wales have risen to the challenge of managing this very difficult financial challenge.
"We have all had to find ways of making savings and at the same time protecting front-line services as far as we possibly can."
Tony Travers, from the London School of Economics, believes sharing officers is a logical step but a big move.
"Many councils in Wales cover very large geographical areas because they are so rural and imagine having a single department running services for two councils over that area," he told BBC Radio Wales.
"I think the reason they are often reluctant (to share) and don't do it voluntarily is because they believe that it's more responsive locally to have their own officers and staff - that's how they were set up.
"The move from that to something where councils are sharing officers may sound obvious and logical but it's quite a big step for them to make."
Liberal Democrat AM Peter Black accused Mr Sargeant of drawing up his proposals for legislation "on the back of an envelope".
He said: "The danger is that a joint appointment at chief executive or chief officer level that has been forced upon councils will prove divisive, unaccountable and ineffective without a greater integration of services.
"It is a profoundly superficial approach to joint working that indicates that the minister is more interested in being seen to do the right thing rather than making progress."