Demonstrated herein is a synthetic strategy for MAMBMC‐type heteronuclear metal‐string complexes (HMSC) in which the terminal metals can be tailored via a displacement reaction based on the relative coordination strength. The stability ruler Ni > Co > (Fe; Mn) > Cd > Cu is derived in this study. Accordingly, MPdM'(dpa)4Cl2 (M ≠ M') can be obtained by the reaction of M' ion with MPdM(dpa)4Cl2 if the relative stability is M' > M. Six MAMBMC‐type HMSCs (2–7) with Pd at the central position are successfully synthesized. Unprecedented properties of metal strings, such as the structures, electrochemistry, and magnetism, are found. The static repulsion between terminal metals can dominate the metal–palladium distances. A shorter distance of Pd–M' at the opposite site can lengthen the Pd–M distance. The redox potentials of metal cores are influenced by this remote static repulsion. Besides, the nature of Cu with a weak spin‐exchange communication can induce the ferromagnetic coupling mediated by the central Pd in CuPdCo and CuPdNi HMSCs, and these are the first examples of ferromagnetism mediated by the central Pd metal among metal strings.