I know next to nothing about East African Football history -except that it isn't up to much.
But they look like a great set of results.
It seems to me that African Football as a whole is getting more & more unpredictable with plenty of teams once considered as "minnows" emerging. These teams may not be serious contenders to actually qualify for the World Cup in the end but can be a match for anyone on their day.
I suppose it's also true that some teams might have a tendency to be "overrated" if not within Africa then outside. If a team has been to the World Cup then they automatically become a "power" and any defeat for them by a "non-power" is seen as a shock.
But - apart from the real African super-powers like Nigeria & Cameroon - who you would expect to be there or thereabouts most of the time - it's probably normal for the standard of a lot of the other teams to fluctuate quite a lot.