Unit drops, and who goes first

So I see a lot of people making lists with low amounts of units to put on the table so they have a better chance of going first, ignoring reserves for that count. My local shop plays that reserves are 'set into reserves' as one of your deployments, meaning if you have the same amount of units as your opponent, and you have 1/2 your army in reserve, you still have the same amount of drops. Whats the correct way to play this?

With reserves as drops I think.
Because (I think in the tyranid Q&A but not o100% sure) it mentions that you even specify in where you put them (underground, in hive nodes, outflanking etc)

Yep, placing a unit into reserves is still a drop. Best way to reduce number of drops is by putting as many units as possible into transports as the transport plus all embarked units only count as a single drop.