Differences at GM plants identifying non core jobs

The UAW claims GM is stretching the definition of non assembly jobs to get more new hires into the lower end of the 2 tier wage/benefit scale.

Good for GM.

By Sharon Terlep, The Detroit News
At least 3 UAW local leaders have sent out notices to their members in recent weeks accusing GM of trying to push through more second-tier jobs than the company and union agreed to under the national contract, and several say those talks have been a point of contention in local contract talks.
GM will begin officially rolling out retirement offers today and expects workers to be gone July 1.
But before the shift can happen, GM and UAW locals that represent dozens of plants across the country must agree on which factory jobs will command an hourly rate about half the current wage of $28 an hour. Under the national contract, lower wages will go to workers not directly involved in building an automobile.
Under the labor deal, signed more than 5 months ago, GM and the union agreed to reclassify about 16,000 jobs as "noncore" automotive work that would command the lower wage. The union and company agreed that those noncore jobs will include work such as moving material, managing chemicals and working in the paint shop.
The agreement laid out general job descriptions for the lower tier workers and rough numbers -negotiating the specifics is up to each factory.
In Arlington TX, the local contract called for 296 jobs to be designated as noncore, while GM is looking to designate more than 400 jobs as noncore. In GMs Orion plant, GM would like to have about 580 noncore jobs at the plant, while local leaders think something like 300 is a more fair number.
These are the kinds of things that have to get worked out at each local before the new hires start work later this summer.

Under the national contract, lower wages will go to workers not directly involved in building an automobile.

The union and company agreed that those noncore jobs will include work such as moving material, managing chemicals and working in the paint shop.
Isn't it as simple as they fall into this catagory or not? Union can suck it if they want people in this catagory to get paid more when they already agreed to this setup.