I wish I had your problems, with that level of on-campus
support.
I think you should consider enlarging your review to teams of people,
possibly groups of 3, who review the proposals in batches of about 10.
You would need a standardized review sheet, which you probalby already
have.  Have the teams representative of the colleges, department, and
rotate the chore.
You need more people reviewing because, there it is really hard for any
one committee member to give a qulaity read to 70 proposals in his/her
own field, let alone one in which they have little experience.
The other reason is that with smaller batches you can expect more
written comments from your reviewers.  I think it is very poor
policy to not give the writers specific feedback on their proposals.
You are missing an great training opportunity for your younger
faculty, and the faculty is getting nothing but a rejection.
Although the possibilities of unding from your committee are
pretty good, not many folks can take rejection without some indications
about how to be more competitive in subsequent years.
I realize that having more readers will be a big chore, but
I think the faculty will understand that you are trying to
give them a fair read and better input after the fact.
Good luck.
Spanky