No - There is a confusion here:
The Spanish machines were equipped part (11 machines) with an Armstrong Siddeley Jaguar (serials 5117, 5118, 5120 to 5129) and part (15 machines) with a Wright Whirlwind R-975-E1 (serials 51102 to 51107, 51109 to 51117)
The first FK-51 machine (ex-prototype, serial 5101) equipped with an Armstrong Siddeley Cheetah IX was also delivered to Spain
In addition an unique machine (PH-AMP, serial number 51108), equipped also with a Jaguar was delivered as a mono-seater with a closed cockpit. This transformation had been made at the Koolhoven factory to assess the possibility of using the FK-51 as a mail plane. It would be soon re-modified in Spain into a two-seater, after a brief evaluation as makeshift night fighter.
Concerning the Dutch machines:
A) All the Dutch LVA (Army air component) machines were equipped with an Armstrong Siddeley Cheetah IX
1) the first 10 machines ordered by the Dutch LVA (serials 5102 to 5111), were unarmed training machines - similar to regular production but with a more rounded tail fin (except for the 5107 which has the definitive tail shape). Their rear fuselage is fabric-covered.
2) the 15 machines delivered to the LVA in 1937 (serials 5133, 5135, 5137 to 5139, 5143, 5145 to 5152) had a machine gun under the left upper wing, and the rear fuselage in aluminium
3) the 29 machines ordered by the LVA in 1937 and delivered in 1938 (serials 5162 to 5181, 5194 to 51101, 51123) had also a machine gun in the rear seat position.
These training machines had an optional cover for the rear seat position to train for night flight
B) The Dutch MLD (Marine air component) machines (serials 5112 to 5116, 5130, 5153 to 5161, 51124, 51125) were equipped with a Wright Whirlwind R-975-E1 and were delivered in three batches in 1936, 1937 and 1938.
C) The Dutch LA-KNIL ( Dutch East Indies Air component) machines were equipped with a Pratt and Whittney Wasp junior
They had 2 machine guns in the upper wing. A total of 60 machines were the subject of 4 successive orders, among these 45 machines reached the KNIL before May 40, the last 20 of these machines having enlarged wings. On the last order of 15 machines, 6 of these machines (serials 51146 to 51151) were under construction and destroyed in May 40.