I'm not sure if people are trying to compare Lennon and De Boer but there is one big difference between the two.
De Boer is at the club that revolutionized modern football tactics 100 fold more than other club in Europe. It is a club that has a strong tactical identity and from top to bottom thinks and embraces football philosophy. Neil Lennon is at Celtic.
De Boer learnt from the greats. Did time with youth, did time with Internationals and then took over a team with a real playing philosophy.
Lennon worked under the lord of anti-fotball for a fair chunk of his career. Went from Reserve coach - first team coach - manager very quickly and then was fortunate enough to lose the only competition he had.
The Dutch league has nothing on the premiership, but it is a hell of a lot better and more competitive than the SPL.
No comparison, IMHO.