Best front or rear is only significant when grip is at its maximum; otherwise, it is irrelevant.
Speed or the road surface (wet, slippery, etc.) might be the cause of the grip limit.
In order to handle steering inputs as well as the centrifugal force produced by the vehicle's lateral acceleration, the front tires endure a greater amount of lateral force than the rear ones.
FWDs are often designed to understeer, which is corrected by increased steering inputs, which is a more natural response for novice or inexperienced drivers. This situation is limited by the front axle's best tires.
In order to adjust for rear wheel slip, the opposite lock must be used; otherwise, the back of the automobile risked passing the front.
Up until the tread was decreased to around 3mm, according to RoSPA research from 2005 (there may be more current data), there was only a little decline in braking performance. 1.6mm is the minimum.
Conclusion: Unless the tyre is already very worn, grip is not really important.