Not necessarily. It depends on what your talking about. For example if you have:
"Company" It get's the most searches (of course) at 100, 000
Then let's say "Company" came out with:
"Company Easy Product" 50,000 searches
Then it came out with :
"Company Easy Product Advanced" 20,000 searches and this was a popular product. Then a few years later it came out with :
"Company Easy Product Advanced To Go" and this is all the new rage because it's a new improved version and everyone is excited about it. It could very well top the one before it at 30-40K a month, even though it has a longer tail.
I'm actual basing this off of some of my long tail keywords that have higher searches that the shorter.