F.N. Peloubet, in The Teacher's commentary on the Acts (1903, Oxford) deals with Lachmann's multiple author theory in passing, in the context of the composition of Acts.
Peloubet (Introduction, xxxv fwd) states:
"VI. THE SOURCES OF ACTS. As Luke expressly says in the preface to his Gospel that he derived his information from the records of eye-witnesses, with which he was perfectly familiar, the same is doubtless true of his treatise on the Acts of the Apostles. ...
...there is no reason for thinking, a priori, that the speeches cannot be historical. . . . The speeches of the leading apostles would impress themselves on the growing community, and would be remembered as the words of the Lord were remembered.
There are some interesting comparisons of the discussion of the composite nature of the Acts with other literature in A. H. Strong's The Great Poets and their Theology."The German Lachmann resolved the Iliad into sixteen distinct and clearly defined layers. Paley has compared the Iliad and the Odyssey to pictures of stained glass made up by an artistic combination of handsome bits of older windows which fortune and time had shivered."The combatants [textual critics] are more and more arraying themselves on the side of the traditional view that both poems are by the same author, and that this author is Homer. But Homer himself may have taken many years for the elaboration of his poems, revising and improving them as he repeated them again and again, so that during those years versions of various degrees of perfection may have been set in circulation.
Goethe in one of his letters to Schiller cites different versions of his own poems, in connection with the theory we have been considering. He had at various times amended and enlarged them; but he did not on that account prove that there was a second Goethe, or many Goethes. "What all this tells us is that subsequent critics and investigators cioming after Lachmann have found that all such naive theories of 'many detectable layers' and 'multiple authors' are at best precarious conjectures and near-worthless. Even, and perhaps especially, reconstructed 'genealogies', based on the alleged identification of various 'interpolations' and layers are simply academic fantasies, their proliferation and variations providing the best evidence of their spuriousness.