Chair, you're in a much more difficult position if you don't call the steering committee, because your problem is then that not only do you not have an additional Conservative to offer views; you do not have any other party representatives, and you're now forced to adjudicate on a paper basis between claims that can be better resolved in a face-to-face meeting of goodwill.
So I don't think it pays to try to avoid having a steering committee meeting, when it's by far the most efficient way to proceed. I think you're actually doing yourself a favour, with respect, if you allow people just to hash it out.
People can submit stuff. It's basically to make sure we've covered all the bases. It's not a negotiating session; it's just basically to avoid misunderstandings. If there are any problems, they can be resolved by committee of the whole.