Name Extension

Hello Momsh! Nag reresearch ako about sa rules ng name extensions (I, II, III) and so far lahat US. Wala yatang Philippines. I am planning to name my second baby like his Dad pero dadagdagan ko mg 2nd name..not exactly the same, so hindi sya magiging Junior. Gusto ko sana gamitin yung "The Second" (II) since sya naman talaga ang second with that name same as his Dad, do you think pwede yun? Would appreciate insights. Thank you!