The research quoted might be a little out of focus of the subject since one have to understand that the benefits of acupuncture might be of a complete different modality: Most research medication versus acupuncture look at benefits which have to do with modalities as balancing bloodpressure and alike so more in the way if a stroke patient in GENERAL will rehabilitate faster with acupuncture than without. The research mentioned, is this within Traditional Chinese Medicine(TMC acupuncture) or Medical Acupuncture? The way of thinking is very different and therefor the choice of points regarded as essential for the outcome of the treatment different.
To my experience acupuncture with a painful hemi shoulder when looked at in a neuromusculoskeletal way can be rather beneficial: look at range of movement of the neck, shoulder, positioning of the shoulder, head. Use triggerpoints to rebalance rest tone and so on. In genral it is not a good idea to needle a muscle in spasm for obvious reasons: If you provoke a spasm how does the needle look like? If though one would needle e.g. Lv3 it might have some effect on spasticity. But first of all you have to know the background of the spasticity, has it purely a neurological background or also a musculoskeletal?
Research of acupuncture in general has been very poor and therefor the chance to find a good research (which can stand the test) on something as specific as rehab and acupuncture is doughtful.