You have 3 main areas here, all dependent on the Service Level Agreement:
1. Agenct's staff in airline uniforms - all over the place, an example at just about every airport;
2. Agent recruiting langauge speakers - depends on the Service Level Agreement - if it's required, it can be done - but at a cost. probably why Alitalia have been bust more times than most people can count!
3. Agent dedicate staff to a single customer airline - it does happen but again, it reduces efficiency so most carriers will allow a % of dedication mixed with a more flexible approach.
Anywhere where the airline has dedicated agent staff AND provides it's own full supervision will be an inefficient and costly operation - but hey, we are talking Alitalia and efficiency and controlling costs are not something that they are very good at.
As more and more on-line and kiosk check-in becomes common the less it is likely to see airline employed people front of house at an airport.