It seems to me that handling agents seem to be reluctant to take on charter carriers than they would in previous years, a wise choice maybe?
Huge seasonal fluctuations in traffic and slot 1/2/3 departures in the summer can really stretch manpower and also equipment, especially when you handle more than 1 charter carrier. Just look at Swissports first wave flights at MAN between FR/TOM/TCX/ZB/LH etc, crazy!