If they had been heavily armed they probably would have pulled it off.
For how long?
The objective was to keep His Flatulence in power. That would give them more time to consolidate their hold on power.
You are not answering the question. That is understandable as the claim that they would have prevailed in a coup is dubious at best. They merely would have delayed the constitutional process maybe by a week at most. The fact that they would have killed prominent members of congress and the administration, not to mention scores of other security personnel, and prevailed, is ludicrous.
Sure, it's ludicrous. But it's not implausible, and coups elsewhere in history were no less ludicrous.
I am sure that the French and Russian aristocrats had a good old chuckle at the absurdity of a few upstart peasants trying to overturn the entire machinery of government. Even after they'd stormed some palaces and killed some guards and even some minor nobles, it was ludicrous to imagine that they could do anything more than cause a few weeks of disruption and disturbances, before the authorities put them in their place, and hanged a few ringleaders.
Certainly the absurd and clownish National Socialists with their spiffy uniforms and polished jackboots caused some civil unrest, got into some fights, smashed a few windows, even shot a few police - but their seizing actual power was ludicrous. Particularly once their cult leader was imprisoned for his role in the Munich beer-hall putsch.
All revolutionaries are ludicrous, right up until they suddenly win, leaving the rest of the population scratching their heads and wondering how on Earth the system collapsed so quickly.
Here's a scenario for you:
Jan 6th. A bunch of "rioters" break into the Capitol, find the Vice President, and a bunch of various senators and/or congressmen, and kill them.
The President declares martial law, and a state of emergency. Under the emergency decree, he is to remain in office until the dead senators/congressmen, have been replaced through special elections. To be called at a future date. Of Trump's choosing.
High ranking military and police officials who are seen not to have prevented this national disaster are arrested, but those officers are in fact selected by their lack of personal loyalty to Trump, not any actual failures on Jan 6th. Their replacements are hand picked by Trump.
Any public protests against these changes are ruthlessly put down, with Fox News applauding the firm actions that should have been taken to save VP Pence and the other senators and congressmen, now being seen to take place in defense of The American Way
TM.
Journalists, influencers, and people who have been publicly unkind to Trump are arrested as part of the response to the disorder. They are sentenced (by judges appointed by Trump) to long jail terms for sedition.
The new election date is pushed out indefinitely; Until it becomes clear that no elections will take place at all. By which time anyone who might speak up is either in jail, in hiding, or in exile.
Which part of that ludicrous scenario is impossible? Or even implausible? Who is going to call a halt to it, and how will they enforce that?