Should we treat them as twins or just siblings? Also need naming help?

are their older siblings all their fathers children? if so y should ye be tryin to keep your babies in line with his previous kids names? I not gone on ne of the above but i like casey and macey as ryming names or but I dont feel they should really even have to have similar names as they are not twins n even if they were they are individuals n deserve to be treated and named unique. it is important that u pick individual names to give them a sense of self and ownership...Remember they will someday grow up and a name is who they are for ever they will not always jjust be 2 cute little babies with matching names...