We’ll make it work conveys two ideas – “We’re in it together” and “This is a commitment.”
There are many substitute responses to “We’ll make it work” – “I’ll try,” “We’ll try,” “Perhaps we can try make that happen,” “Let’s hope we can make it happen,” etc. None are as powerful. The beauty about “We’ll make it work” is that it galvanizes both sides.
And, if you don’t want it to galvanize both sides and really make a commitment, just say no.
There are those few times when you might want to use “try” as a cop out response or as a genuine attempt at communicating the uncertainty around things you don’t control.
But, for the most part, it is on us to avoid mucking around with weak promises.