Field Hockey: 1v2

Hi, I have a complicated set of questions which shows my limited understanding of field hockey. I’m coaching a U13 team of 22 girls in the U.S., and each player has at least one year of experience. I’ve played FH only with my kids though I have a basic understanding of the game and its concepts from playing soccer and basketball, and watching games for many years. I've coached kids in other sports, this is my first year coaching field hockey. (If you’re wondering why I’m coaching, no parent in my community with playing experience would step up and my daughter loves the game.)A warming: This is a long set of interrelated questions but your taking the time will be greatly appreciated. Problem: The core problem is responsibility conflicts on defense. My players understand concepts of zone and marking separately. I don’t know enough to explain how they should manage the two responsibilities in field hockey. I “get it” by playing other sports for so long and therefore am able to see how they aren’t “getting it.” For clarity, I have in mind two kinds of offense players: OP1 (has the ball); OP2 (doesn’t). The girls understand that zone means each has a certain area to protect; and marking, how to position themselves in relation to offensive player without the ball (OP2), and when to mark tight vs. loose, and to what it means to follow her mark. Situation 1 (Off-ball play): if one OP2 (OP2-A) enter zone of Left Midfield (LM), for example, how LM apply marking principles (a) when OP2-A enters zone; (b) a second OP2 (OP-B) enters zone; (c) if OP2-A leaves zone, LM should (i) release OP2-A and stay on OP2-B or (ii) follow OP1-A and leave OP2-B. How resolve these zone/marking conflicts for other positions: CM/RM? For RD/LD/CD? (We play a basic 3-3-1-3.)Situation 2 (Support teammate pressuring ball (D1). The girls understand basics of channeling, approaching OP1 to tackle, and how D2 should support D1 (e.g., D2 is cover for D2). We’ve done drills (1v2), but transferring into game situations is difficult. How explain D2 maintain zone responsibilities (a) if supporting D1 means D2 (a) vacates assigned zone and/or (b) or OP2 in zone). Situation 3 (Forwards). They are having trouble with changing defensive responsibilities from within the opposing team’s quarter of the field, the middle quarters, and our quarter of the field nearest to our goal. I’ve thought about just making the defense solely marking but that creates its own chaos and tires out the girls. Without these basic concepts, the result is a joyless scrum: players are bunched up on defense, so if there’s a turnover, the players are too close together for a counterattack. This is unfortunate because the speed of field hockey games should appeal to kids in the U.S. Thanks