I read the article below with a sense of astonishment, 99% of leads do not convert?! Certain this was just an alarmist use of statistics, I took the time to find the Forrester research referenced. It is here (page 4).

It seems that the numbers have been reported correctly; in a B2B environment 0.75% of leads become customers. This would suggest that the odds of getting a B2B lead to convert are far worse than getting a single number in roulette (37/1 or 2.7% is 3.6x better odds) and that ignores the cost of chasing all those other leads.

In other words, applying a funnel approach to B2B marketing is far less scientific than taking your entire marketing budget to Las Vegas. 

Also, the advice that you should "tweak where necessary" does not seem appropriate; that's like saying "be sure to play some baccarat to hedge your bets". 

If you are involved in high-value B2B sales, have a think about using Expert-to-Expert Marketing instead.