How can I write a better script for a summing block using the 'MATHLAB FUNCTION block'

I am trying to replicate the operation of a 'summing block' with a 'function block'. I've read the documentation ( https://www.mathworks.com/help/simulink/slref/subtract.html = scroll to the bottom end) and it says that the summing block reorders the inputs, greatest number first and then adding them. I wrote a script that reorders three inputs and adds them. With integer values, it works. When I sum the results from transfer functions' outputs into the adder I designed, the result is not correct.

Below I posted the script I wrote. I would appreciate if someone finds a better solution for this, Thanks in advance

function y = fcnAdd(inp1,inp2,inp3)

y=0;

if((inp1 > inp2)&&( inp2 > inp3))

    y = inp1+inp2+inp3;
end
if((inp1 > inp3)&&(inp3 > inp2))
    y = inp1+inp3+inp2;
end
if((inp2 > inp1)&&(inp1 > inp3))
    y = inp2+inp1+inp3;
end
if((inp2 > inp3)&&(inp3 > inp1))
    y = inp2+inp3+inp1;
end
if((inp3 > inp1)&&(inp1 > inp2))
    y = inp3+inp1+inp2;
end
if((inp3 > inp2)&&(inp2 > inp1))
    y = inp3+inp2+inp1;
end
if ((inp1 == inp2)&&(inp2 == inp3)&&(inp1 == inp3))
    y = inp1+inp2+inp3;    
end

[Birdman]

Can you share your model?