If COMEY & BRENNAN Really thought the Steele Dossier was TRUE,

They would have believed that there was enough "evidence" there to Stop Trump.

However, they then went ahead with setting up 1) the Fake Trump Tower Meeting and 2) they attempted to set up a Fake Papadopoulos meeting with Russians using Mifsud.

That proves that that both Comey and Brennan KNEW that the Steele Dossier was full of crap and therefore they needed more "Russian" evidence to Bolster their case against Trump even if it was fake / weak.

Create enough smoke and people will believe there is a fire.