It was the Poles who played the key role in decrypting the Enigma.
You must have missed in the article the line or two about the pre-war start the Poles got on cracking the code, and the French-brokered sharing with the British.
Absolutley true. The Spanish "contribution" was to send what essentially were training messages that gave the British confidence. According to Roger Kahn, the German military enigma was effectively unbreakable in principle, using 1940's technology, even with the Polish contribution. The British relied on German sloppiness and lack of disciple, in other words, poor COMSEC practices.
The problem for the Germans was that the operators did not believe that anyone would expend the kind of effort required to break the enigma machines. Other than poor COMSEC, the Germans gave the British lots of help. On Hitler's birthday, birthday greetings from the various Army commands gave the British a pretty reliable plaintext crib. On occassion, one command would complain that a message had been sent using the old key, the offending command would obligingly retransmit it in the NEW (!) key. The first transmission in the old key only risked the message sent in that key, by retransmitting in the new key, they divulged the new key to anyone who had the old key!
Read Kahn's book, it's fascinating.