Well..... at 1 1/2 yrs they are plenty mature to breed so I would say it is a good chance anything that came in heat is bred.... We put 18 mo old bulls in to breed with about 15-20 head for their first season.... they are plenty old/mature enough at that age.....
I get the whole alpha thing, and do appreciate you wanting to abide by your dad's wishes.
As I said, ASK for opinions, LISTEN to what is said....THEN make YOUR OWN DECISION. I will tell you that some of the "olde timers" that I used to ask and listen to their opinions, were very much of the "mindset" " well, ..... this is how my grand daddy did it, and it was good enough for him......." and were very against change. All the "old ways" are not bad. Some are better than some of the fancy new stuff.... But there have been vast improvements in the way some things have been done...take AI for instance.... and in today's marketplace the margins are tight. So things like not pregnancy checking, and then feeding a cow for a year to find she doesn't calve, is a WASTE OF YOUR MONEY in feed and she is taking up a spot that a productive cow could have. Losing a calf or 2 because you don't believe in ANY vaccinations, is just throwing money away. Make a bonfire with 100 bills for every calf that dies or every calf that is not born. WASTED..... But, going back to more grazing, granted the "newer ways are more intensive" is getting back to the way cattle were meant to be, not all put in smaller pastures and you spending all your time taking feed to them. They are meant to graze and they should "rustle their own grub" so to speak.
IT IS A BALANCE. That is why I also suggested to talk to an extension agent, find out if they are having any seminars/talks etc and go to them. I still go to all I can and I have been doing this for over 40 years...... you can always learn something., and it is a great way to network and maybe meet someone who you can share some time/work/help with. You never know.....
Because your pastures are split up, I get the feeling that your dad was trying to do some type of rotational grazing. That is more "modern" than the old way of fencing in the land, turning the cattle out and they ate what they wanted, when they wanted. Often, they would graze the "best tasting spots" into the ground and it never had a chance to regrow. By rotating the cattle, they should graze it all down better (more cattle smaller area) and then moved so it has a chance to recover and grow back. Of course the weather has a big say so in that.... But if you think to back 100-200 years, the buffalo grazed in herds of thousands, they ate it down, trampled it down, then MOVED to the next place. They were natures own way of rotational grazing. In our more controlled and limited way, that is what so many of us try to do today. You can actually run a few more head in rotational grazing because it will actually improve the stand of grass. It needs that break to regenerate. Maybe your dad and grandfather did not see eye to eye on this.... it has taken alot for a few of the older generation here to see that.
At least if he has talked about some calves dying from blackleg, hopefully he is willing and a believer in vaccination.
Like I said, we do not do alot of the vaccinations that the vet used to push and I personally do not like modified live vaccines ( a throwback to older ideas), but using killed virus vaccines often means an extra trip through the chute and that is not always practical. We also do very limited "chemical worming" like pour ons. We try to keep and breed for animals and from animals that seem to have a greater resistance to parasites. Another whole "lecture". We do use it some, especially with bought cows that we know nothing about to give them the chance to start off "fairly clean" inside and out.
Please keep us posted....