Perkins vs cummins vs caterpillar.

In our diesel engine industry of today, especially for power generstion purpose, we cannot under estimate the benefit from these 3 engines mentioned above. Perkins is an absolute loved by most, caterpillar is reliable( using it though) and cummins, a rugged spec.  But we keep asking questions about which is the best.  Perkins as we all know is a very popular engine, and has unparralled spare parts availability, caterpillar is more or less a premium engine( some say if u have the mony go for caterpillar) and cummins is a very rugged and seems capable of witstanding more stress. But for all these pros, they still have there disadvantages.  Perkins for one i know is now so common, and hence more availability of fake parts, and hence less reliability. Even some of the so called manufacturer in Nigeria import lower quality components to assemble their machine,in a bid to cut cost,. This has really made me doubt the reliability of our made in Nigeria, perkins powered generators, though their are a few companies you can trust. On the other hand caterpillar is more or less a monopoly,their is just one officially recognised dealer in Nigeria,as such no room for healthy competition. Thats why people prefer to go for the aftermarket during maintainace Or the fake parts.  Cummins has also has similar monopoly issue like caterpillar, and also its parts are somtimes not readily available.
Still contemplating which is the best.