(Sendou ooku shite fune yama ni noboru;
“With many boatmen, a ship will climb a mountain”)
Too many cooks spoil the both. With too many crew members trying to steer, a ship can become so lost that it leaves the water entirely and ends up on a mountain-top. If too many people are trying to lead or give directions, then it becomes increasingly difficult to choose and stick with a single direction or vision for whatever the team is working on, leading to poor results.
This one is a functional sentence, comprising two complete verb phrases. The first begins with the noun 船頭 (sendou), literally a ferryman or boatman. As is often the case, here we might expect a particle, but it isn’t really necessary grammatically so none is forthcoming. Next we have the adjective 多い (ooi) in conjunctive form because it is modified by the following verb. The verb it is linked with is する (suru), often translated as “to do” but here more like “to make (something be a certain way).” It appears in conjunctive te-form in order to join the two halves of the saying together.
The second phrase begins with subject and object, respectively 船 (fune), “boat/ship,” and 山 (yama), “mountain.” The former could be marked with subject particle が (ga), but again the particle is elided because grammatical function is clear from the sentences structure. The object is marked, but with the directional particle に (ni) rather than the object marker を (wo). Finally, we get the verb 登る (noboru), “to climb (a tree, mountain, etc.)” in sentence-final form.
Replacing に with the more specific directional particle へ (e) or 登る with 上る (same pronunciation) is acceptable, and does not significantly change the meaning. The verb structure of the first part may also be replaced with a simple conditional form 多ければ (ookereba).
This saying is of decent age, attested to since 1638 and included in a treatise on poetry called 毛吹草 (Kefukigusa).
(“Sendou ooku shite fune yama e noboru to iwan bakari ni, Makioka-ke no choujo ga tsune ni kaji wo ketteidzukeru kengen wo nigitte dare ni mo inin suru kehai wa nakatta.”)
[“As if to say that too many cooks would spoil the broth, the eldest daughter of the Morioka family always kept a firm grasp on her authority over household matters, without the slightest hint that she might delegate anything to anyone.”]