It all depends on where you want the clipping to occur.
If you want clipping only from the drive pedal (as opposed to the amp or the next pedal in the chain) then increase the drive on the pedal and reduce the volume (down to unity gain) to avoid a volume increase from an amp with lots of headroom.
Alternatively, you could use a second channel in the amp block with the same settings except for a reduction in the amp block level (output) to compensate for the increased input from the drive pedal. Using Scenes you can co-ordinate the engaging of the drive block with the switching of the amp channel.
When using "real" single channel amps, then using pedals is necessary to get from very clean to very dirty. However, with Fractal products you can turn any single channel amp into a four-channel amp so that you need not rely solely on pedals to provide the range from clean to dirty.
Many players deliberately set their clean sound with the amp closer to its headroom limit (edge of breakup) so that with either their guitar volume low or light picking they have a clean sound, but turning up their guitar volume and/or picking harder causes the amp to begin to break up. Then when they engage a drive pedal in front of the amp, the increased output from the pedal (above unity gain) will push the amp into overdrive. This may have some volume increase, but much less because the amp is compressing when being overdriven. Again, if the volume increase is too much but you prefer the sound to the first option (getting all clipping from the drive block) then use a 2nd amp channel to compensate at the output of the amp block.
My personal preference is to use multiple channels of the amp block so that I have clean, gritty, dirty and boosted sounds just from the amp settings. Using different channels in the amp also allows me to adjust other amp settings (e.g. Bass/Mids/Treble/Presence) as I go from clean to dirty while maintaining the same volume when switching between them. If I wanted I could even change amp models from one channel to the next, but I generally don't do that. I typically don't need a drive block, but sometimes I will add one to give a slight push (and shaping) to the dirty, or boosted channels (I don't generally use it with the clean channel). Because the amp is compressing in these channels the volume compensation is pretty similar for each of them. Of course if it was too high for one of them then I could just use multiple drive block channels and adjust the output of the drive block for the channel I am using it on (and use Scenes to co-ordinate the switching of the amp and drive channels together).