You never know. This question cannot be answered. It depends on the individual cats.
Two cats together (we mix ages all the time and have for decades) will always fall into a coexistence pattern. There will be a top cat. That cat will have an attitude like Obama toward the other cat. “I don’t give a blank” what younthink, will be top cat’s attitude. (And it could be either cat in your situation, but id lean toward the younger male, who should be fixed but even so)
Whether their relationship will be peaceful or not depends on the cat who isn’t top cat. The cat who isn’t top will either Care Deeply that he isn’t top, or he will not care so much. If he or she cares deeply, they will have a hiss and scratch relationship except for feeding time if their bowls are near each other. (As long as you feed them healthy canned food - kibble is poison for cats - at two regular meal times). If he doesn’t care that he’s not top, they might play together nicely and sleep together (not in the first month or two).
It really depends on the individual cat.
Watching cats get along, you can sEe why they say, in human relationships, the person who cares least has the power. It’s very true. The one who is screaming “I wanna be in charge!” Is the one who just isn’t.
You’ve brought up an issue that I’ve never been able to figure out.
There is such a division of opinion on canned vs. dry food for cats - even among professionals; and especially regarding male cats.
Why do you think canned food is best?
(We have always given our cats canned food for their two main meals, and dry food ad lib. Except for one cat who developed a severe ear problem, and one that contracted cancer, we haven’t had health issues; and all other cats simply died of old-age complications.)
But I’ve never really known what the best diet is.
-JT
Thank you for stating this! We don't need any more kitties with diabetes.
There is dry food available which is grain free. Also watch for other carbs... Tractor Supply has an allegedly grain-free dry food, but it is perhaps not low enough in carbohydrates since they use potatoes in it.
Innova Evo is one premium food that has a grain-free dry food available, and there are others out there. Read labels.
You generally don't want to feed dry food exclusively over the years, since that may lead to slow dehydration, predisposing the poor cat to renal failure.
I try to feed my cats canned food (whether cat food or human-grade canned fish or other stuff) at least once per day. I leave out dry kibbles for free feeding.
Remember that cats evolved as desert animals, and they get some of the moisture they need by drinking the blood and body fluids of their prey. I guess this is why they love canned food which has gravy on it.
I found that feeding cats canned human-grade fish (such as salmon, tuna, sardines, or mackerel) will cure and prevent dry eyes. Apparently the EFAs in oily fish are utilized by mammals' bodies directly in mucous membranes, which the eyes have.
Good luck!