Which plane Qatar going to replace?? Plus they buying whole world of new jetts F15, EF, Rafale for tiny country it's an over kill.
They also picked a fight with the Saudi-UAE coalition and faced sanctions as a result. The Qataris want to hold their own (geopolitically speaking) in the Arab world and I don't blame them. For a small country that faces the threat of aggression by the Saudis and their allies, such a step is not over-kill: it is a force multiplier to make up for their smaller size.