The link below has a lot of useful information on status effects. The general rule of thumb is if the same symbol is used, they override.
In this case, Wu’s gambler stance is a pretty unique special. Few are overwritten by it, however some have caps that effect it. See below for Wu’s special “image” and those that override it. Rigard is an attack up so you should be fine.
| Name | Icon | Description | Overwritten |
|---|---|---|---|
| Attack Up |  |
Increased offense |     |
| Gambler Stance |  |
Offense greatly increased with reduced accuracy |  |