awk '
NR==FNR {
# assuming column 1 is the same for all files, remember it.
# only need to do this for the first file
col1[FNR] = $1
}
{ for (i=2; i<=NF; i++) sum[FNR,i] += $i }
END {
for (i=1; i<=FNR; i++) {
printf "%s", col1[i]
for (j=2; j<=NF; j++) printf "%s%s", OFS, sum[i,j]
print ""
}
}
' file1 file2
1 6 5 11 6
2 4 8 5 14
Deve trabalhar com nawk, gawk e mawk.