Let's say macro-mechanistic evolution is real and true. Could God have still entered the picture and moved some parts of the evolutionary tree here and there? Of course He could, if He exists.
Yes, of course, God could be responsible for affecting or directing life to evolve in certain direction.
But you are forgetting that biology is still a BRANCH OF science, and evolution (as well as all mechanisms in evolution, including Natural Selection) is a FIELD IN biology.
And as scientific discipline, biology required that any statement (eg in theory or hypothesis) made, needs to be "falsifiable" and "testable". Essentially, what this mean is that the statement needs to be empirically verified (hence, it would need "evidences") before it can be accepted to be true.
Trying to assert God into the picture in biology - more specifically evolution - WOULD require that there be evidences for God.
Well, there are no direct evidences for existence of God, which make YOUR ASSERTION or CLAIM of God "directing" evolution - "speculative", "unfalsifiable" and "untestable" - and let's not forget - "wishful thinking" - and would require creationists such as yourself, to use all sorts of logical fallacies to twist God into science.
How many times have I stressed that for any statement to be scientifically verified and validated, it needs evidence, Evidence, EVIDENCE???!!!
You cannot - like every other creationists that I have come across, here and elsewhere - seem to grasp the concept of evidence.
Any statement, no matter how many logics you may apply to the statement, cannot be objectively true, unless there are testable evidences to back up the statement.
Take for instance, the theoretical theory on the multiverse model (actually it is "models", because there are numbers of different scientists advocating their own brands of multiverse) can be very logical - with all the mathematical equations (proofs) being belt out...and yet, not a single model of multiverse is testable in reality.
Multiverse is logically feasible, but not empirically feasible, which makes every single models "not true".
But the thing is, not only is your assertion about god's intervention not empirically possible, it is also not logically possible.