The only thing I'd wonder is if its hedging & not fencing is that the goats might cause a few escape routes or weak spots by eating the hedging, Saying that though if a cow wants to escape or just run through a hedge it will, & its rather difficult stopping 500kgs + of beast when it doesn't want to play ball. Although I can count the times on my hands where our cattle have escaped & theres normally a reason.
Also if it's a lot of grazing cattle & goats & sheep all graze differently, so cows like long grass & will graze that down but don't like short grass whereas sheep are short grass grazers - but if stuck in a field of long grass will devour it. This is why a lot of farmers combine sheep & cows, & also one sweetens the grass & land & 1 sours it. So it balances it out. This is often why you see a lot of farmers rotating the fields so: cows, then sheep or a mix then rest it then maybe hay-making, then repeat & again the same is involved with horses. But some grazing may be suitable for cows but poor for sheep & vice versa.
Now your goats probably won't eat huge amounts of grass as their browsers, but they will eat your hedges.
Also its fine in summer / spring but whats happening come winter? Are you buying in hay? or can you make your own based off the type & amount of land you'll own. As it's likely that at some point that both species would need to come indoors for a while or have access to a shed, although it also depends on the type of cattle you get as some native breeds like Galloways & Highlands you can winter outdoors, & remember you will at some point need to REST your ground & preferably rotate it, otherwise your going to be having to put more nutrients back into it & potentially find your stock with worm problems, because of over use. It's also a good idea to try & find out what was last used for.
Also with cattle before buying check if its a TB prevalent area & talk to locals & check the land for badger activity. Just because I'd hate for someone to start with cattle & 6-18months down the line find their stuck with a TB problem as I'd never wish that on anyone. Hope this helps & good luck.