1. If Tim hadn't retired he would have been here with us now.
To me, 1 is broader in general, because you can apply most of it to the past:
If Tim hadn't retired he would have been here with us yesterday/on that day.
That is to say, to a past which can be extended to the present/now, as in 1.
Also, to me the "would have" brings more uncertainty, close to
impossible, as in contrary-to-the-fact situations (which this is).