Does this help?
set interfaces ge-1/3/0 per-unit-scheduler
set interfaces ge-1/3/0 vlan-tagging
set interfaces ge-1/3/0 unit 0 vlan-id 100
set interfaces ge-1/3/0 unit 0 family inet address 172.16.1.1/30
set interfaces ge-1/3/0 unit 1 vlan-id 200
set interfaces ge-1/3/0 unit 1 family inet address 172.16.1.1/30
set class-of-service interfaces ge-1/3/0 unit 0 shaping-rate 4m
set class-of-service interfaces ge-1/3/0 unit 1 shaping-rate 2m
set firewall policer LB-policer logical-bandwidth-policer
set firewall policer LB-policer if-exceeding bandwidth-percent 50
set firewall policer LB-policer if-exceeding burst-size-limit 125k
set firewall policer LB-policer then discard
set interfaces ge-1/3/0 unit 0 family inet policer input LB-policer
set interfaces ge-1/3/0 unit 0 family inet policer output LB-policer
set interfaces ge-1/3/0 unit 1 family inet policer input LB-policer
set interfaces ge-1/3/0 unit 1 family inet policer output LB-policer