I do not wish to get into a war either.

Whilst the 45-70 in some of the new loadings is far better than CIP/SAMMI specs, it is running on the ragged edge for the rifles in which it is being utilised. They are hand/custom loads.
Calibers that are generally considered "adaquate" do so with factory spec ammo.
LA rifles when brought up to 4000flbs are dammed unpleasent to shoot, they are light for that sort of power. I've shot a 7 1/2 lb .450 LA and I would much prefer my 11 1/4 lb 450#2

The lever action design ( I have several in smaller calibers and indeed compete internationaly with them) is more prone to jamming than say a DR or a Mauser. It does not have the camming power for sticky extraction. Look at the volumes written about the dreaded "Marlin jam" It is not in my opinion a good DG rifle for that reason.

Great penetration (by 45-70 standards) is being achieved by what are to all intents and purpose flat nosed solids. However they are not as good as one will get from a .375 of even .275 with solids.

The use of flat noses is mandated in LA rifles, thus they will not range out as one can with BA designs using RN or Spitzers. Due to the stock design they are generally not MOA rifles either compounded by the temperature changes in Africa.Thus they are not great plains game rifles. They fall short of the 458+ cal classic DG rifles in stopping power at end of barrel distences so they are not the perfect choice here.

Thus for me they are neither fish or fowl.

Looking at the Buff photo, that rifle is running what looks like a 3-9 x 40 scope. Most of the posters here know how a lot of safaris are being conducted in terms of shooting from prepared hides and vehicles. So yes a 45-70 marlin is fine for a head shot from a fixed position, but so would a 30-30, .358 etc etc. That old boy clearly was prepared for exactly the type of shot he took. With the greatest of respect to him, If he could chase buff around the bush for a few hours I will eat my hat.

The 45-70 and LA guns generally are rightly popular because of the nostalga factor, as are some of the old British calibers that posters here love to hunt with.
I think that it is great to hunt with whatever gives you most pleasure and of course they will kill along with the best given correct bulet placment and good fieldcraft. And in a lot of ways it is an achievment to get that trophy with a less than ideal caliber.

But when one waxes lyrical about "adaquate" it is really about what one wants in ones hands when TSHTF or when the trophy of a lifetime is 250 yards off and for me at least that is not a LA.

But if it about what one wants when a nasty pack of feral dogs either human or canine approaches I will take my .357 Marlin every time, ten aimed shots in 5 seconds will get the job done..but I don't want to hunt with one that has been hotted up to do what it was not designed for.

Regards