Assumption 1: The Saltwater Crocodile is the absolute top of the ecological food pyramid in its habitat, the transitional zone between land and water, both in terms of physical strength and the maximum size of potential prey organisms.
Verification of Assumption 1
Confirmation of the first assumption is made possible in several ways, which together quickly lead to a clear result. First, however, a clarification is needed. The definition of the assumption refers to the adult, or at least averagely-large sexually mature individuals. Very young Saltwater Crocodiles, on the other hand, are far from being at the top of the food pyramid of their habitat, as is the case with practically all other large animals species.
The first two pictures show several specimens, little more than two or three weeks after hatching from their eggs, in a coastal freshwater swamp. These small crocodiles are slightly longer than 20cm. They also feed by hunting other animals, but their main prey still consists of insects. They themselves are potential prey for many species of birds, reptiles and fish. In fact, it is likely that only five percent will reach sexual maturity, and then become about two meters long. This puts them in a position where there are very few natural enemies left, in terms of physical superiority.
When they are nearly four meters tall, like the specimen shown in the picture below, there is no other species in their habitat that could challenge their position at the absolute top of the food pyramid. There are several reasons for this. The first is easily observed by looking at the anatomy of the head, with its huge mouth and teeth.
The visible features of the skull are accompanied by an extremely high jaw muscle efficiency. According to empirical research, Saltwater Crocodiles have the highest proven biting power of all animals currently living on the planet . There are unconfirmed estimates that very large specimens of the Great White Shark have similar biting force. However, the point here is to prove the absolute top of the food pyramid in the habitat of the Saltwater Crocodile. The core of the habitat and food pyramid lies in the transition zone between land and water, while that of the shark is the open ocean. Because the Saltwater Crocodile is also often in the sea and - as I will show later in detail - also hunts there, there are overlaps in its habitat with that of sharks. The centers of the two habitats, however, are clearly different.
The high efficiency of the muscle tissue plays a decisive role in the further property of an extremely high attack speed from resting. According to the results of measurements with camera technology, the animal moves forward within the first quarter of a second at a speed of 12 meters per second . It can thus cover a distance of three meters from a submerged position on the edge of the shore to land in 0.25 seconds.
For physical reasons alone, no potential prey will attain the reaction time needed to avoid such an explosive attack. That is why in Australia, for example, one of the most important rules published by the authorities in the distribution area of crocodiles is the observance of a sufficiently safety distance from the edge of the bank.
Their extremely high attack speed is achieved by the tail. This consists of very firm, horn-like skin, bones and very efficient muscle tissue. This can be seen in the following picture (which was taken by chance, the animal was not intentionally provoked by me), as the Saltwater Crocodile, in a typically threatening gesture, strains its tail muscles over the last two thirds of its length. This part of the tail forms a large recoil surface in the water by the laterally flattened form, together with high horn fins. Before shooting out of the water for capture or a fight, the tension of the muscles extend into the rear back, and within a small fraction of a second, an enormously high recoil force is converted.
The Saltwater Crocodile appears like a Manifestation of extremest Physical Violence
The characteristics of the Saltwater Crocodiles outlined here, the huge mouth, the big teeth, the highly efficient muscles and the enormous recoil force by the tail, are supplemented by an almost totally armored body surface, allowing this animal to appear like a manifestation of physical violence.
This coincides with them being the largest of all species of crocodilians, which besides true crocodiles, include alligators, caimans and gharials, with a body weight sometimes over a ton and a maximum body length of over six meters. With it, they lie far higher in its spread area than any such pure land animals that also feed through hunting other animals. There are certainly some overlaps of their habitats: as the only potential competition (in the sense of assumption 1) within the circulation areas of the Saltwater Crocodile, however, the Asian tiger could possibly enter into consideration. However, their core habitats are again not identical here. Apart from this, even the biggest tiger males, with their potential 300 kilograms of body weight, would probably not be equal to a large Saltwater Crocodile in a direct confrontation.
Beyond this, the maximum size and the potential average size of the directly and individually attained catches of Saltwater Crocodiles are higher than those of tigers and sharks. From Australia and South Asia, various confirmed witness statements state that individual Saltwater Crocodiles can overwhelm and kill prey up to the size of adult cattle bull - even those weighing a ton -.within a very short time, sometimes less than a minute. Where humans hold such "farm animals" in large numbers along the banks of rivers, they can even become the regular prey of the Saltwater Crocodiles. A link to a corresponding report from Northern Australia  can be found below, for verification purposes.
There are reports that sharks and tigers also overwhelm and kill similarly large prey in individual cases, but this concerns rare observations and other, far slower speeds of the catching process. Also, the exclusion of direct competition exists anyway, in the sense of assumption 1, by the different habitat centers.
There is actually no organism in the habitat of the Saltwater Crocodile, at the transition of land and water, which represents genuine competition, in the sense of assumption 1, at the absolute top of the food pyramid. It should be noted here that I have not found any claims to the contrary in scientific or other sources, even over the course of extensive research. Assumption 1 can thus be established as true.
 Erickson et al. 2012 Ecology and Evolutionary Success of Crocodilians: PLoS ONE. Bd. 7, Nr. 3, 2012, e31781. doi:10.1371/journal.pone
 Ph.D. Dr. Adam Britton https://crocodilian.com/cnhc/cbd-faq-q4.htm