Mixed olefin polymerization catalysts, methods for preparing olefin polymers using the catalysts, and polymers obtained therefrom are disclosed. The mixed catalyst system comprises the combination of (a) a Group 8-10 transition metal complex of a bidentate or tridentate ligand comprising at least one nitrogen donor selected from Set 1, (b) either a Group 8-10 transition metal complex of a bidentate or tridentate ligand comprising at least one nitrogen donor selected from Set 1 or a bidentate ligand comprising a nitrogen-nitrogen donor selected from Set 2, or a Group 4 transition metal complex of a multidnentate ligand comprising at least 1 cyclopentadienyl or indenyl ring selected from Set 3 or a titanium or chromium Ziegler-Natta catalyst selected from Set 4, and optionally (c) a compound Y.