Thoughtful, objective analysis reveals that all Gods are but partial manifestations of the same purusa, Sri Krsna, and all Goddesses partial expressions of the primal sakti, Sri Radha. Krsna possesses all attributes of divinity found in other incarnations as well as aspects found in him alone. There can be only one God, yet . . . he has many expressions of himself. ~ Swami Tripurari (Rasa: Love Relationships in Transcendence, p. 71)
Hinduism is like the Irish Tourist Board slogan with a picture of a country road and the legend the road you're on will take you there. One can see from the opening quote of a leading figure in ISKON that they regard Krishna as the main highway. In that sense they are unusual and fall outside the standard 'all paths are one and no one path is superior' doctrine. They also reject the saguna (formful)/nirguna(formless) characterisation of Brahman. Vishnu then would be an incarnation of, a ray of, Krishna. The division of doctrine into the vyavaharika and the paramarthika namely that which can be understood as limited and provisional and that which is beyond conceptual understanding and is a matter of realization; is also rejected by Swami Tripurari. That quote is taken from a statement by Dr. Michael Sudduth who became a convert to Gaudiya Vaishnavism (G.V.).
Obviously Hinduism is so broad a church that it encompasses all positions including proselytism but speaking purely from the vyavaharika position it is logically counter to the main understanding of sanathana dharma which baffled missionaries. 'Yes, yes', the target group would say with that assenting wobble, 'Jesus is God, all are God'. If they were already there how could they be brought there. Samuel Taylor Coleridge thought this was due to a lack of concentration:
APHORISM XVIII. (Aids to Reflection)
Examine the journals of our zealous missionaries, I will not say among the Hottentots or Esquimaux, but in the highly civilized, though fearfully uncultivated, inhabitants of ancient India. How often, and how feelingly, do they describe the difficulty of rendering the simplest chain of thought intelligible to the ordinary natives, the rapid exhaustion of their whole power of attention, and with what distressful effort it is exerted while it lasts! Yet it is among these that the hideous practices of self-torture chiefly prevail. O, if folly were no easier than wisdom, it being often so very much more grievous, how certainly might these unhappy slaves of superstition be converted to Christianity! But, alas! to swing by hooks passed through the back, or to walk in shoes with nails of iron pointed upwards through the soles—all this is so much less difficult, demands so much less exertion of the will than to reflect, and by reflection to gain knowledge and tranquillity!
It is not true, that ignorant persons have no notion of the advantages of truth and knowledge. They confess, they see and bear witness to these advantages in the conduct, the immunities, and the superior powers of the possessors. Were they attainable by pilgrimages the most toilsome, or penances the most painful, we should assuredly have as many pilgrims and self-tormentors in the service of true religion, as now exist under the tyranny of Papal or Brahman superstition.