Interestingly, I totally understand your brother's POV. IMO, my sister keeps trying to take care of our mother or run her life for her and it's so clear to me that it directly relates back to the fact that my sister wishes that my mother had been a more involved parent. It's like my sister is subconsciously thinking "My life/psychological health would be better if you had been a better parent and I'm going to prove that by doing a better job parenting you in your old age than you did for me when I was young." or something like that. Total fusion.
Clearly, I don't know the details of your sich but would you "take care" of one of your sons in the way you are taking care of your father or would you feel like it might interfere with his personal growth if you did? Are you just assuming that your father is incapable of personal growth at his age and your current actions are just sort of a first step towards preparing for his death? I know people who are over 90 and living active, independent vital lifes in which they manifest a great deal of personal responsibility.
"Tell me, what is it you plan to do with your one wild and precious life?" - Mary Oliver
