I am looking for non-isomorphic finite groups that
have the same order
have faithful real irreducible representations
the smallest dimension of faithful real irreducible representations are equal
Are there any examples, besides the cyclic and dihedral groups?
Are there any examples?
An equivalent question would be:
Are finite subgroups of $\operatorname{GL}(n,\mathbb{R})$ which are not subgroups of $\operatorname{GL}(m,\mathbb{R})$ for any $m<n$ uniquely determined by their order?
The smallest example is the symmetric group $S_3$ and the cyclic group $\mathbb{Z}/6\mathbb{Z}$.