General Tactics
Team positioning
Point
Builds meter extremely fast. He can utilize assists to help keep his pressure stable, low blockstun assists can especially help him possibly get some grabs as he pressures his opponent.
Mid
His assists are good for neutral for some characters thanks to its space coverage and acceptable blockstuns to help the point character maintain their pressure. At times, Broly can also be pretty meter hungry as he can deal tons of damage with his EX moves and supers.
Anchor
Broly can have a lot of trouble on maintaining pressure or even starting a combo due to his unsafe and slow normals, though some have good reach which could compensate it all by a bit. And without assists and enough meter, it'll be impossible for him to get a sliding knockdown from anywhere. However, his neutral is good enough alone thanks to his projectiles, decent mix-ups with his grabs, and super armor on some moves. He could still also deal lots of damage with enough meter as well. It'll be difficult to conststently play him as an anchor, but it's possible in a way.
Picking Teammates
Wall bounce assist Gives Broly amazing corner carry in almost any solid hit using Broly's MASSIVE 5M and if he already has the corner they can be used to combo into sliding knockdown using DR or 6H into 214M. Wall bounce assist include: Gogeta A, Goku Base A, Android 17 A, Hit B and Jiren A.
Basic beam assist Gives Broly good corner carry using super dash as well as high damage corner extensions into sliding knockdown. Beam assist paired with 236S in neutral is a reliable way to cover most of the screen and force your opponent into blocking. If the beam assist connects in neutral Broly can confirm off of it using 236M.
Goku Base A assist like other wall bounce assist gives great combo extensions but Goku Base's should be highlighted as it's particularly quick and has decent blockstun adding to Broly's block pressure. Broly's grounded 236LM can easily setup spirit bomb and is also his Z Change level 1. j.236LM can also set up spirit bomb by directing Broly up back in the corner and immediately Z changing into spirit bomb. This paired with Goku Base B assist allows Broly to reliably two touch off of most hits.
Adult Gohan Z changing from Broly's grounded 236LM into Adult Gohan potential unleash allows Gohan to follow up with a DR. This can also be done with other fast supers like Ginyu and Trunks.
BASICALLY ANY ASSIST!!!
Blockstrings
2L > 5L > 5LL > 2M > 5M > 5H > 236L
5M, 5H, 5S 236X and 236S are all reflect proof, use them after putting a gap in your blockstring. 5H and 236S are particularly strong for covering reflect as they both have vertically high hitboxes and 1 hit of armour.
Example: Will allow Broly to keep the pressure going and adds to his command grab pressure
2L > 5L > delayed 5LL (Reflected) > 5M > 2M > 2MM (Reflected) > 5H > 2H (Reflected) > 236S