Referencing Vladimir Lenin, "What is To Be Dope?" (1902), Lenin is here calling for unity among socialist thinkers, emphasizing that criticisms made by socialist thinkers against one another’s thoughts strengthen the enemy (bourgeois ideology). Put in other words, Lenin is saying that when members of the group are seen disagreeing on their ideas and goals, this is used by the enemies of the group as proof that the group is wrong.
Do you agree or disagree? Is it more important that a group (any group, not just the socialists of 1902) project a united front, or that the ideas of each member of a group be heard?
There is merit to what Lenin is saying; although I don't subscribe to his political beliefs. However, he is right in alluding to the fact that when a group that purports to be united comes across as disagreeing with each other (members disagreeing with one another), they in fact, appear as divided. Consequently, outsiders to the group will use this as ammunition to discredit the group as a whole and their ideologies.
It doesn't mean a group (any group) is wrong when its members bat ideas back and forth and disagree with one another. It does mean that thye're perceived as being in turmoil somewhat; they're perceived as not cohesive as a group and without a focused strategy and message.
Therefore, a group should encourage debate among its members and allow for disagreements as they formulate their ideologies, policies, procedures, statutes, and such. However, this debate and clashing of ideas, and the attendant arguments, should take place internally at the group's meetings and internal functions. When presenting themselves to the outside world, the group should maintain a united front of cooperation so that the focus is on their message and not on their internal squabbles.