The order in which processors are attached to FPGAs can be significant on some multiprocessor modules. The IDE always attaches processors in the order in which they are listed in the Diamond source view. You can change this order by right-clicking the name of the processor you wish to move and selecting Move Processor Up or Move Processor Down.
Lyrtech processors are identified by their DEVICE attribute and so the order in which attachments are made is not significant.