perl -MO=Concise -e 'print map $_->[1],sort{$a->[3]<=>$b->[3]}map[lc,$_],1,2,3'
-e syntax OK
r  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 2 -e:1) v ->3
q     <@> print vK ->r
3        <0> pushmark s ->4
k        <|> mapwhile(other->l)[t8] lK/1 ->q
j           <@> mapstart lK/2 ->k
4              <0> pushmark s ->5
-              <1> null lK/1 ->5

;; You can see the ->[1] access and you already know there's only two elements.
p                 <2> aelem sK/2 ->k
n                    <1> rv2av[t1] sKR/1 ->o
m                       <1> rv2sv sKM/DREFAV,1 ->n
l                          <$> gv(*_) s ->m
o                    <$> const(IV 1) s ->p

;; You can see the entire sort block got optimized into something native (I guess. It's certainly not in perl anymore)
i              <@> sort lKMS* ->j
5                 <0> pushmark s ->6
-                 <1> null sK/1 ->6
-                    <@> scope sK ->(end)
-                       <0> ex-nextstate v ->-
-                       <2> ncmp[t4] sK/2 ->-
-                          <2> aelem sK/2 ->-
-                             <1> rv2av[t2] sKR/1 ->-
-                                <1> rv2sv sKM/DREFAV,1 ->-
-                                   <$> gv(*a) s ->-
-                             <$> const(IV 3) s ->-
-                          <2> aelem sK/2 ->-
-                             <1> rv2av[t3] sKR/1 ->-
-                                <1> rv2sv sKM/DREFAV,1 ->-
-                                   <$> gv(*b) s ->-
-                             <$> const(IV 3) s ->-
b                 <|> mapwhile(other->c)[t7] lK/1 ->i
a                    <@> mapstart lK/2 ->b
6                       <0> pushmark s ->7
-                       <1> null lK/1 ->7

;; You can see the array get allocated and can see it has only two elements.
h                          <1> srefgen sK/1 ->b
-                             <1> ex-list lKRM ->h
g                                <@> anonlist sKRM/1 ->h
c                                   <0> pushmark s ->d
e                                   <1> lc[t6] sK/1 ->f
-                                      <1> ex-rv2sv sK/1 ->e
d                                         <$> gvsv(*_) s ->e
-                                   <1> ex-rv2sv sK/1 ->g
-                                   <1> ex-rv2sv sK/1 ->g
f                                      <$> gvsv(*_) s ->g

7                       <$> const(IV 1) sM ->8
8                       <$> const(IV 2) sM ->9
9                       <$> const(IV 3) sM ->a