My understanding is that the Angles were from the Frisian islands and nearby coast, the saxons from further inland and the jutes from Jutland, i.e. what is now the border area of Germany and Denmark and further north bordering on the lands of the Danes.
Since they had lived close to each other for some time, their language and accents must have been similar.
I remember going to NW Germany on school exchange visits. My penfriend's parents grew up speaking Alt Deutch which had quite a few similarities with English, e.g. salt und pepper rather than modern German saltz und pfeffer.