Oh it's completely possible , but like I said a large endlie wont likely eat an ADULT Senegal, i also said fine as juvies as long as the difference in size is not too drastic. Stick a bichir in with an endlie twice the size then ya it could eat a smaller bichir and probably would as soon as it's hungry!
Bichirs are more fragile when small, it's more important to watch difference in size when young sizes. However in my experience at ~ the 10" mark they bulk up a bit and from that point on are fine with even the biggest of bichirs. My endlies are 20 & 22 inches, and live with 10" bichirs, smallest I've dared introduced was an ornate at 8-9" , that's border line but had no choice because it hit the size where it was eyeballing the smaller 4-5" senegals and del's in my growout and it turned out fine.
It's when young that they have the greatest risk of eating other bichirs, they are so thin and narrow that sizes that they should be kept with others of similar size. But once they top the 10" mark most species have enough bulk that they all get along fine with larger bichirs.( EDIT: mis spoke, not in all cases because even long rope fish are still quite thin, they live full time in the growout tank)
It's just my experience with them, I keep Ornates, Senegals, Del's, Endlies, Lap's and rope fish , and in all cases I found that it's around 10" where they are big/bulky enough to be recognized as other bichirs and not prey.
of course with all that said your dealing with a predatory fish, if if hungry enough they can turn on each other, and other factors like factors like if they have be fed live, or if they've been kept solo and you drop a smaller fish in from of them, it will also increase the odds of one eating the other.