The website for Kuwait Airways says the following and I find it confusing: https://www.kuwaitairways.com/en/is/free-baggage
ECONOMY DIMENSIONS FOR NORMAL CHECKIN
Length: 90cm, width 65cm, ht 75cm
So which one is it? Since 90cm(l) + 65cm(w) + 75cm(h) = 230cm is greater than 158cm.
Emirates on the other hand is very clear in it's statement:
The total dimensions (length + width + height) of an individual bag should not exceed 300 cm (118 inches). Bags exceeding this limit will not be accepted as checked luggage. For travel from Dammam International Airport, an individual bag should not exceed 215 cm (84.64 inches).