Hi Tommy.
Advantages of haylage are : you can cut it shorter, bale it less dry, store it outside. And it’s rarely a fire risk, whereas hay got a little damp can set on fire if it’s not stored and managed very carefully.
Advantages of hay are it doesn’t deteriorate provided it’s stored correctly, whereas haylage does deteriorate even when the wrapping stays intact, and quickly once the air gets to it. We’ve fed four year old hay to sheep, with no ill effects, and regularly feed two year old hay to sheep and cattle. Haylage is best used in the first winter, although if it’s pretty dry and is looked after properly (so the wrapping isn’t damaged), it’s usually okay in the second winter.
For a smallholder, hay is generally easier to use. It weighs less as it dries after baling. I really struggle to lift and carry a small bale of haylage, whereas I can manage hay bales reasonably easily. You can use hay at whatever pace suits you, just re-tie the bale as you remove some to keep it tidy, whereas haylage needs to be used quickly once the wrapping is breached. Also, wasted haylage will damage the ground more than hay (although both will if left in the field where the livestock were fed.). Oh, and wrapping is the most expensive part of the operation, so making hay is a lot cheaper than making haylage. And the used wrap has to be disposed of, which costs money too - we had two dumpy bags of plastic last year, and our local recylicng scheme charges £15/dumpy bag full (that’s with us delivering to them.)
So the first question is, do you have airy dry storage? If not, you’ll have to make haylage anyway. (It’s still better to store it under cover but it will probably survive one season outside.)
Second question is, do your local contractors have the equipment to make small bale haylage? If not, you’ll have to make hay and will have to find somewhere to store it under cover. A big bale of haylage will feed 15 adult cattle for one day, or 40-50 sheep for 4 days, and must be used up within a couple of days of opening for cattle, or 3-4 days for sheep. So for us small fry, they’re too big to be useful. Having said which, there are people on here who manage to re-wrap bales and use them over a week or so, but it’s not something I’ve done or would recommend.
Third element is the weather and the ground. I used to farm an upland farm, very wet ground, in north Cumbria, and some years we just couldn’t get hay at all, it all had to be silage or haylage. On that farm, it took four days to make small bale hay except in very exceptional years, when we could get it in three days if the ground was bone dry to start with and it stayed sunny and dry throughout. Many times we’d cut, hope for four days dry or pretty much, but end up wrapping it for large bale haylage. Occasionally we’d cut, expecting to be making haylage, but the weather gods would smile, and come baling day it was dry enough to cancel the wrapper and make it into large bales of hay. (You can make large bales a little more damp than small, and can let them air in the field for a week or two, so they’re not a fire risk when they come into the shed.)
Timing is variable depending on ground and conditions. Sometimes it makes sense to cut the outside few rows of the field earlier in the season and wrap it. The bare ground around the outside helps the ground to dry so you’ve a better chance of making hay of the rest of it.
We very rarely managed to make hay in June, always hoped to make it in July, and often ended up making it in August and sometimes September. The problems with making it later in the year are a) the days are shorter and the sun (such as it is) less hot, so the drying time each day is less, and it’s a race to get it turned and rowed up on baling day, and baled and stacked (and often under cover too as it was nearly always going to rain later that day, or the next

) before the evening dew starts to form; b) there’s less nutrients in the crop the later in the season - the best hay is made before the flower heads seed; c) the crop gets thicker and longer as the growing period goes on, and a thicker crop is harder to get dry enough to bale, and needs turning more often to let both the crop and the ground beneath it dry - and every turn damages the stems slightly, so the crop becomes more friable and can crumble in the bale - no use for hay, but still usable if wrapped. (But you need to keep turning it to dry it if you’re in those sorts of conditions. We’d turn it immediately after cutting, again the next day - sometimes twice, usually again on day 3, and again before rowing up on baling day. On drier ground in parts of Yorkshire, they’d only need to turn it once

)
If your local contractors are set up for small bale haylage, given your area sounds similar to ours - wet and inclined to be rushy! - you might do best to go for haylage the first year or two, and explore making hay once you’ve got the other aspects of your operation running and settled in.