We discuss previous studies on SO(N) linear sigma models (LσM) and some limits of phenomenological interest. These models suffer a spontaneous symmetry breaking (SSB) down to SO(N−1), with the appearance of an associated vacuum expectation value (vev) f, a heavy scalar degree of freedom (dof) with mass M and N−1 massless Nambu-Goldstone bosons (NGB). These models are of a high interest for beyond Standard Model extensions where the Higgs boson is identified with a pseudo Nambu-Goldstone boson (pNGB) that appears in the SO(N)/SO(N−1) SSB. It gains a non-zero mass m due to soft explicit SO(N) symmetry breaking (ExSB) terms in the Lagrangian. In particular, we will focus on the soft breaking pattern SO(N)ExSB⟶SO(4)×SO(P)SSB⟶SO(3)×SO(P−1), with 4+P=N, e.g., via new beyond Standard Model (BSM) gauge boson loops. The SO(4)/SO(3) are the electroweak (EW) chiral/custodial groups and the associated SSB is exactly the Standard Model (SM) one, giving mass to the W± and Z gauge bosons while avoiding large corrections to the oblique T parameter. The comparison of this type of models with the current phenomenological situation, close to the SM (m=0.125~TeV, EW vev v=0.246~TeV, M>O(TeV), ghWW≈gSMhWW) sets important constraints on the LσM parameters: there is a very small mixing between the heavy and light LσM massive scalars and the pNGB h is essentially SM-like, the low-energy effective field theory (EFT) couplings are very close to the SM ones, and a large hierarchy ξ=v2f2≪1 is needed in these LσM near the SO(N) limit (and ξ much smaller than a certain ratio λ2λ1 of quartic LσM couplings in the general case). Likewise, we note the existence of strongly coupled scenarios with a hierarchy m2∼v2≪f2≪M2.