We are converting a first floor room to a master bath. It will be a fairly open layout, limiting venting options. There is a basement below, but to conserve useable basement space, and because of where we need to connect to our main drain/sewer line, we plan to run a horizontal drain below the bath floor and as near to the basement ceiling as possible. We plan to connect a toilet, shower, whirlpool tub, and 2 sinks directly to the horizontal drain line. We plan for a single vent off the horiziontal drain, about midway, rising through a wall and out the roof.

My questions are:
If each fixture drain is within its critical distance from the vent, does it matter what order they connect to the horizontal drain? And does it matter if the fixtures are before or after the vent?

Specifically, we plan: toilet (<3'), shower (<3'), vent, tub (~3'), sinks (separate vent connected back to main vent)

Does this work? Thanks.