Disorderly types randomly crash trains — not right (10)
I believe the answer is:
anarchists
'disorderly types' is the definition.
(anarchy is a lack of order)
'randomly crash trains not right' is the wordplay.
'randomly' is an anagram indicator (I've seen 'roaming randomly' mean this).
'not' suggests deleting specific letters.
'right' becomes 'r' (common abbreviation).
'crash'+'trains'='crashtrains'
'crashtrains' with 'r' taken away is 'cashtrains'.
'cashtrains' anagrammed gives 'ANARCHISTS'.
(Another definition for anarchists that I've seen is " revolutionaries".)