Article II, Section 4
The President, Vice President and all civil officers of the United States, shall be removed from office on impeachment for, and conviction of, treason, bribery, or other high crimes and misdemeanors.
There is ample proof of Trump's wrongdoing. That is all that is necessary. This is not a criminal proceeding and does not require that degree of scrutiny.
In the year 2019 there are many lawyers that have become legislators. That is simply a preference of voters. But, legislators are civilians, they are not JAG Corps. They are to defend the USA Constitution WITH CERTAINTY. That is their level of responsibility.
The Declaration of Independence was signed by a few lawyers; Adams (considered the best of them, defended the British troops after the Boston Massacre-most were acquitted), Thomas Jefferson, James Wilson, and George Wythe (professor of law).
Among the 32 farmers of the Constitution the lawyers, were Alexander Hamilton, James Wilson, and George Wythe.
The USA Declaration of Independence and USA Constitution are primarily signed by civilians and farming was a way of life of many civilians.
Impeachment is an "indispensable remedy," not a legal proceedings.