In this work, a theoretical model is proposed to describe the tendencies for the formation of local regions of homogeneous magnetic ordering in binary substitutional alloys with strong electron correlations, in which the type and size of such regions are determined mainly by changes in the electronic structure. Such systems include, in particular, transition metals alloys. Numerical calculations are performed in the generalized Hubbard model to determine the magnetic homogeneity regions at 0 K in fully atomically disordered b.c.c. alloys. As shown, even with constant values of electron concentration and Coulomb repulsion potential of electrons at one site, the changes of both type and sizes (in wide range) of homogeneous magnetization regions are possible due to only changes in the concentration of alloy components. Moreover, at certain concentrations of the alloy components, restrictions on the permissible types of magnetic ordering are possible in comparison with one-component systems. The behaviour of multicomponent magnetic crystals is significantly more complex. For their description, one should take into account the main aspects of the mutual influence of the atomic and magnetic subsystems by adjusting the electronic structure. This not only puts additional requirements to the relevant theoretical approaches, but also opens prospects to improve and develop some traditional and novel methods of magnetic systems diagnosis, in particular neutron and positron spectroscopies.