Convoys are a bit shorter but about the same diameter as the VG15. Maybe a Convoy with a 18350 tube. Will make it quite a bit shorter.

You might like the DQG Tiny 18650

Emisar D4. Does get quite hot during prolonged high lumen runs.
http://www.mtnelectronics.com/index.php?route=product/product&path=80&product_id=855

Olight S2R Baton. Nice light. A bit pricey.
https://www.amazon.com/Bundle-Rechargeable-Flashlight-3200mAh-Battery/dp/B01M0I6FZC/ref=pd_lpo_vtph_tr_t_2?\_encoding=UTF8&psc=1&refRID=249H8KEX4QF2CKXNV71A

I have missed quite a few but I’m sure the guys will show up with some more good suggestions.