Fairly standard grenadier/molotov build but with a fun addition : Overwatch.
It's quite a situational card but you can make the most of it with offensive accessories. It grants 5 temp health per kill for nearby allies if you are 15 meters away. Sounds pretty good with your AOE throwables right?
You need a bit of communication with your team. But when you throw a pipe bomb for instance, you can tell your teammates to come nearby the explosion to get a ton of temp health. This is why we build Down In Front, in order to not hurt the team.
Same thing applies to molotovs, gas cans, they can last a long time and if you have a nice funneling your team can get free temp health.
You can throw grenades at your teammates if they are overwhelmed.
15 meters isnt that difficult to reach and the AOE of your throwables is wide enough.
This build should work really well with a frontliner.