Just have your programmers ask questions here, very few people are going to find interest in helping you guys for free, but we well absolutly help out if you/they have questions about how to go about implementing certain aspects of a game, so don't wait to be told what to do, instead ask what the best way might be to do something. you are also college students, why don't you ask your professors to check over things and ask questions to them?

I'm just trying to figure out how to encourage the team to get that initiative

some folks have it [initiative] some folks don't. them that do, will, them that don't - will eventually become a liability not an asset to the team.

you really need it [initiative] in spades to be a good gamedev. else you're never be "gone gold".

Just have your programmers ask questions here

I am a producer and director and have already done internships in LA

Based on what I can read between the lines here, it sounds like the real dilemma is a project management problem.

Here's how I see it:
1) Your two programmers are going to be the backbone of the project. They're only two people, so they're going to be the bottleneck which limits the speed of progress. That makes them the MVP's of the team. Generally, with a "real life" project, you'd have your programmers go through and create a working prototype of the game. They'd make the skeleton and test it out, and you'd skip all of the art production until you have the core game mechanics in place. How long it takes to create these mechanics depends entirely on your programmers.

2) 13 animators and artists? That's a lot... That means you have a 13:2 artist to programmer ratio. With 13 artists, I would expect some turn over and people quitting the project. Be prepared for at least 1-2 people quitting. Also, that's going to mean that someone needs to manage them all.

3) nobody is getting paid, right? So, that's going to be a huge, huge risk for the project. There is no compelling incentive for anyone to continue working on the project if they just don't feel like it anymore. So, they'll work for 1-2 months and start bailing on you. Maybe you can afford to lose a few artists since you have 13, but you cannot afford to lose your two programmers. If the programmers abandon ship, the whole project is in danger of failure.

4) There was a hint at a deadline, but no mention of project scope and timelines. Please, please, please, make sure that you work on an under scoped, achievable project for the timeline and staffing resources you have available, for the sake of everyones first game dev experience on the team. It's better to deliver a 100% complete tiny game than get 50% done and then abandon the project because its too big. This will require a hard assessment of your programmers abilities and past experience. If they've never made a game before, producing a game like asteroids or space invaders would be sufficiently challenging.

5) Personally, I wouldn't spend a minute worrying about marketing right now. It's a distraction and tends to make people feel important before they've even done anything -- that's not quite good. Focus on the production of the game, and when you get to 90%, then focus on promotion. Oh, by the way... 90% complete is really 50% complete because the last 10% takes 50% of the total project time. ... you are accounting for schedule overruns, right?

6) The learning curve for UE4 and your programmers learning to program a game is going to cost about 3 months of time to become 100% proficient.

7) Who will maintain the project after release? How will revenues be collected and distributed?

Anyways, I would spend 2-3 days right now going over the feasibility of the project and doing risk assessments and working out risk mitigation strategies. An ounce of prevention is worth a pound of cure :) Don't get 3 months into the project and find out that it's not possible to complete it with your resources (time, money, skills, team).