I think that your shooting needs would be well met by any rifle with a maximum velocity of no more than 2,800 fps. For all the deer maybe a 140 grain bullet at that speed. For the wild boar something above the continental suggested minimum advised weight of their 10 metric grammes. So that means 155 grains or better 165 grains or 175 grains.
The "long action" 284's all have a big advantage over the 6.5's or the 270's and it is - with the possible exception of the venerable 6.5 x 54 that of bullet weight. Quite simply even the 270 "tops out" with factory ammunition and reasonably priced factory bullets at 150 grains.
The "long action" 284's be it 7 x 57 Mauser, 7 x 64 Brenneke, 280 Remington or most 7mm Remington Magnum can all handle 175 grain bullets seated well out. This ranks then ahead of either of the "medium action" 284's the sometimes overall length critical 7mm-08 Remington or the moribund 284 Winchester.
For pretty much ALL European hunting I'd say that the 7mm Remington Magnum (or even the old 275 Holland and Holland Magnum) is all you ever need if you handload.
If you don't handload and only use factory ammunition then I'd have had, twenty years ago, slight second thoughts about the 7mm Remington Magnum as being too powerful. But not know. Just get Remington's "Lite Load" with a 140 grain bullet at some 2,800 fps. Perfect!
Two caveats.
The first is that to get full 7mm Remington Magnum performance you will need a full length barrel. If you go 22" you are pretty much sacrificing an extra round in the magazine and your hearing for nothing that the 7 x 64 or 280 Remington can do in a 24" barrel and with a extra round in the magazine.
The second is to check what overall length of round your proposed 7mm Remington Magnum purchase can handle. If you 165 grain or 175 grain bullet has to be seated back into the case you just lost all the powder space the larger capacity case is supposed to give you. (That's also why I rule out most rifles chambered on a "medium action" receiver for the 7mm-08 Remington). Might as well have got a 7 x 64 Brenneke or a 280 Remington to begin with! Or a 7mm-08 built on a "long action".
I looked at a nice Holland and Holland in 7mm Remington Magnum last year and rejected it. Why? Because for what I want and the shooting I do and intend to do (including driven wild boar where factory ammunition only might be required) I thought that 280 Remington was the better choice in a standard weight rifle. I could equally have chosen 7 x 64 Brenneke. They have all the velocity I'll ever need with any bullet weight.
I've also that irrational foolish belief that I need that extra round! Either that or being absent minded I prefer all five of my cartridges in the rifle where I know where they are and the reserve five rounds in my pocket in an old military clip.
But! 7 x 64 Brenneke isn't cheap and as far as the UK goes 280 Remington is almost as rare as an "exotic" wildcat cartridge! You'll always find 7mm Remington Magnum and if you handload it will make you a superb all around cartridge. Just keep it at 2,800 fps
If you don't handload? For those muntjac, roe and red shot "off the end of the barrel" in woodland? Get some Remington 140 grain "Lite Load" in your magazine or to use 175 grain bullets which will give you that lower velocity as factory full throttle standard load 140 grain bullets will wreck the carcase.
Lastly because of its American "plains game" origins with factory full throttle standard load 140 grain bullets the 7mm Remington Magnum will make a seriously good highland stalking weapon with a 24" barrel for those 150 to 200 yard long shots on the hill.