As neither states cuts of meat, the ability to use both are available.
As for "latitude to include a range of delicious non-piggie additions"
On both, I suggest you check your own country's ability to deliver on food quality promises. Caveat emptor.
Prior to throwing stones at others.
Spam Original Ingredients:
Pork with Ham, Salt, Water, Modified Potato Starch, Sugar, Sodium Nitrite
SPAM(R) Classic | SPAM(R) Varieties
Note, no stated meat %.
Ma Ling Ingredients:
Pork Meat 72%, Water, Ham Meat 10%, Salt, Mustard Flavour, Oitati Starch, Sugar, Stabilisers E451, E450, Thickener E407a, Spices, Antioxidant: E316, Preservative E250
MaLing Luncheon Meat 340g | Canned Pork and Ham | Asia Market
Note, meat % sated, 72% + 10%.