I'm not defending your BA, but what types of grievances are you talking about? Are they supervisors working (Art 3, Sec 17) or pay discrepancy grievances (Art 17)? If they were the former, did the members accurately record/state the times supervisors were working, with witnesses?
Most of the time, a business agent is going to have a percentage he'll be willing to settle a supervisors working grievance at without taking it to panel; the incentive here for the union is to get the grievance settled without having to pay the filing fee to get it on the docket. The incentive for the labor manager is to settle the grievance for the least amount of cost for the company and avoid setting any new precedents that might favor the union. The wiggle room in between are the actual merits of the grievance; ie. is a supervisor being written up for the 5-10 minute period it might take to cover a bathroom (not a regular 10 minute relief period) break, a supervisor being written up for clearing an egress in a truck, did the company exhaust the doubles list in calling employees in when short-staffed, was there an "Act of God" (belt burned out, weather delays caused by sleet or snow, etc.), etc. There's also the strength of the case itself and how well it might hold up at panel, including verifiable witnesses and a pattern of similar behavior from management.
That being said, unless the BA was handling a stack of grievances that consisted of piss breaks and the occasional jam break, then settling for what amounts to 10% of the requested remedy is bull****.