Your play style for Gazlowe determines his talents.
Gazlowe is a strange hero. First of all: He is a melee hero with NO MELEE SKILLS. Other melee heroes can charge, cleave, evade, root, stun, combo......But Gazlowe has none of these. Even at level 20 with Mecha-Lord, he has to walk to his enemy and land his plain "face" hits.

Here is my tips for Gazlowe:

1, The turrets are much more important than Gazlowe himself in team fights: Turret can do decent damage. It constantly slow the enemy. It can absorb quite a few hits. Gazlowe take no punishment for losing turret. They even drop Scraps! So all you have to do is to place as many turrets as possible.

2, Gazlowe himself should focus on buildings and minions, even during team fights!! Turrets attack minions first. Cleaning the minions will make turrets focus on heroes. With Robo-Goblin he take down buildings and minions in seconds. He can also take Scraps to make even more turrets.

3, land the Xplodium Charge cleverly. It is THE longest stun from normal skills in game. It do change the fights. It require a lot of practice for positioning.

Scrap-o-Matic Smelter + Reduce, Reuse, Recycle = allmost forever on the lane
The key of this play style is to RECYCLE. Always dismantle the turrets left behind and build new ones. Scraps will shorten your cooldowns. Under perfect recycling pace, it will be one new turrets every 5 seconds and a lot of explosions. Gazlowe play draw game against Zagara on lane. But if you keep pressure she will finally Hearthstone due to the mana problem.
I always prefer Robo-Goblin because it works all the time. You will be very busy on the map. Enemy will regret if they leave you alone. If your teammates can distract the opponents somewhere, you are likely to sneak all camp on the map.