Hey @Benjamin Sulka,
I think these numbers depends on a couple factors, such as your market, property type, and overall goals.
10% for future property management: If your goals are to get your properties under management as quick as possible, then it would be worth it to keep this the same. In my opinion, if you are going to be living in the same area as your rentals, I would not even factor property management in right now. Down the line if you start to have too many properties to self manage, increased rents/lower interest rates may allow you more room to do so. Also, there are a lot of great softwares out there that basically take care of what property managers do, so you could look into that instead.
10% vacancy: In my market, 5% vacancy is plenty, this is something that you will need to figure out for your particular market. A google search or talking with investors in your area would be best.
10% cap ex: I think 5-10% here is okay. It depends also the condition and age of the property. The older and broken down the building is, the more you want to put away.
5% for repairs: Again, this will depend on the property condition, but I also reserve 5% for repairs because I have an old house.
5% for lawn: If you plan to live in the area, I would just buy a used lawn mower for $100 and do it yourself. BUT, this is personal preference, if you are trying to make this a passive investment and don’t want to be cutting the lawn, then 5% is probably fine.
Hopefully this helps! Good luck!