You are complaining that IMC is offering several options?
Btw, its done the world over. For instance, CL class offers 4.8L, 5.5L and 6.2L with the "same shape". Thats only in v8 engines. Then the "same shape" comes with 5.5 and 6.0 v12 engines. Add a mix of 5 speed and 7 speed automatic to choose. Thats a range of 1.4 L to choose from.
IMC is only offering within a range of 0.5L, yet you're complaining. If you feel 1.3 is under-powered, you're free to choose the 1.6 or 1.8. Leave the 1.3 for those who find it hard on the pocket to run a 1.8 in terms of taxes and petrol.