Since selecting any sponsor is all the same, and even a 'no sponsor' would yield you the same sponsor revenue, I have an idea to make it more interesting.
An example is as follows. Make it such that Sponsor-A gives your club 100,000 USD in 7 days.
And sponsor-B gives 400,000 USD in 28 days.
etc.
And you cannot change your club's sponsor once you've chosen it. You can change it only after the end of a season/year so that you can consider a new one. This will perhaps ensure that manipulation doesn't occur. A sponsor is signed for a year/sponsor to go with it.
I hope you get the idea. It can make managers think and plan in different ways, according to their needs. It will also make competition and finance more interesting. Anyone with me?