Yes. It is necessary to attribute providence to God because it belongs to prudence to direct other things towards an end whether in regard to oneself (as for instance, a man is said to be prudent, who orders well his acts towards the end of life, but in God Himself there can be nothing ordered towards an end, since He is the last end) or in regard to others subject to him (and in this way prudence or providence may suitably be attributed to God).
Two things pertain to the care of providence--namely, the reason of order (ratio ordinis), which is called providence (providentia) and disposition (dispositio); and the execution of order (executio ordinis), which is termed government (gubernatio). Of these, the first is eternal, and the second is temporal.
Providence resides in the intellect but presupposes the act of willing the end. Nobody gives a precept about things done for an end unless he wills that end. Hence prudence presupposes the moral virtues, by means of which the appetitive faculty is directed towards good.
Even if Providence has to do with the divine will and intellect equally, this would not affect the divine simplicity, since in God both the will and intellect are one and the same thing, as we have said above (Q19).