In Sri Vaisnavism, the Alwars are considered to be incarnations of the club, conch, etc of Visnu. Is it a prerequisite that one believe this in order to embark upon the path of Sri Vaisnavism.
The difference here between the two sampradayas with regard to their founding members, Sri Caitanya and Sri Ramanuja, is that it is central to Gaudiya Vedanta to acknowledge the divinity of Sri Caitanya, whereas this is not the case with Ramanuja and the Sri Sampradaya. Furthermore, it is central to Gaudiya Vedanta to acknowledge that Sri Caitanya is svayam bhagavan, Sri Krsna and moreover Radha Krsna combined. Without acknowledging this, one cannot be a Gaudiya Vaisnava in any real sense of basic sambandha jnana.
Now if one really understands that Sri Caitanya is svayam bhagavan and one also understands what svayam bhagavan means, then one understands that svayam bhagavan is never alone. Indeed, all of the incarnations of Godhead have their entourage. Who is the entourage of svayam bhagavan? Will they not come with him when he appears? How could they not and how could he be what he is without them (bhedadbheda)? The blessed Kavi Karnapura has tried to answer these important questions.