I'm not a lawyer so you may be correct.
Clause 6.2 says:
> In the event AstraZeneca's ability to fulfill its obligations under this Agreement is impeded by a competing agreement entered into by or on behalf of the Commission ... AstraZeneca shall not be deemed in breach of this Agreement as a result of any such delay due to the aforementioned competing agreement(s).
It does, as you say, come from a different perspective. It seems to be saying that if the EU has other agreements, and those other agreements impact AZs ability to meet its obligations, then AZ isn't liable.
So the competing agreements are not agreements between AZ and third parties, but further agreements either between AZ and the EU (most likely, perhaps to cover additional EU orders which may run in parallel for example) or other agreements between the EU and third parties (maybe if those agreements restrict AZ ability to obtain equipment or materials).
Either way, thanks for leading me to look again. This stuff is so complex and interwoven it's almost like we need a specialised profession to help clarify the legal aspects.