There is good sense in what both Simone and wheels write, but I'd take issue with wheels on this bit:
The decision is made on planning grounds alone and the status of another application is not a factor to take into account.
AFAIK if it came to an appeal it would be based on the argument by Asda/camsfc that their edge-of-centre site passes the 'sequential test' because there is no suitable town centre site.
If SMBC are to win that argument, and successfully make the case that there IS a suitable town centre site, then the status of the Kirkland scheme will become a critical deciding factor. As long as Kirkland don't have a tenant, then Chadwick/Trinity Street is by definition not a suitable site, because, er, no supermarket chain deems it to be 'suitable'.