Rather, just like in politics, one can lie, slander, libel, invent and utilize a whole gamut of dirty tricks in an attempt to win elected office.
That's exactly my point. The defense team in this case has to hammer and destroy the MOTIVES of the prosecution, not just the FACTS of the case. And the optics of a bunch of House managers getting exposed as liars in an impeachment proceeding will have tremendous political value for Trump.
The Democrats know this. That's why they appointed a group of stunted misfits from safe Democratic districts to serve as the House managers in this case. That's also why the Trump team added a group of GOP House members to its defense team who had previously exposed these lies in public impeachment hearings last fall.
So, once again, if the novel House lawfare standard is allowed, then impeachment will forever be cemented as just another political process. The attack should not be on the obvious tactical elements & weaknesses of the managers, articles & process that you have identified and called out. Rather, it should address the very heart of the determination of whether this particular event should establish a precedent for future generations.
That's up the Senate: accept and seal the fate of the republic; reject the legitimacy and create a threshold standard. Most importantly it would establish requirements not only for (criminal) actions, but also common legal standards for due process, evidence, witnesses, etc that were entirely absent under the 'political' doctrine used by the House.