Complex sentence: Emperor Yūryaku is suspected to be King Bu, but the date (and indeed reality) of Yūryaku are uncertain, and the Korean reference may be anachronistic, but the compilers clearly felt that Emishi troops were credible in such a context.
Split into simpler sentences: Emperor Yūryaku is suspected to be King Bu, but the date (and indeed reality) of Yūryaku are uncertain, and the Korean reference may be anachronistic. However, the compilers clearly felt that Emishi troops were credible in such a context.