Note that, for terrain, the "Table Cover" does count as 1 entry. This would be AT LEAST a 4'x4' piece.1 Warhammer 40,000 or Horus Heresy unit. Only 2 of these units may be an Independent Character. All other units must be either be a significant unit of infantry, vehicle(s), monstrous creature(s), bikes, or the like. What constitutes "significant", of course, is subjective, but try to keep them reasonable... 1 Rhino, 1 Daemon Prince, 3 Obliterators, 5 to 10 Tactical Marines, 3 to 6 bikes, etc. While 1 Attack Bike technically counts as a single Unit, it's not quite in the spirit of "significant".
1 significant piece of terrain. What constitutes “significant” is subjective, but imagine any Games Workshop kit would be considered a legal Commitment (1 Bastion, 2 Vengeance Batteries, 4 Quake Cannon Craters, 1 Woods, etc). If you use this as your guide, it should be easy to figure out what works. You may only count the table cover itself as 1 entry.
4 Battlefleet Gothic "units". A squadron of at least 3 Escorts counts as a BFG unit.