Why not join a stat board instead of the army?
A stat board is great place for diploma holders to pursue their part-time degrees.. though the pay may not be super high for a diploma holder since you will just be a management support staff but the environment is conclusive for furthering your education.. Seldom need to work late so you can leave on time for your night classes...
Furthermore, since the government is always pro-upgrading.. the ministry have to support this ethos also.. some stats boards will grant you 12 days of study leave every year to go for your exam preparation... Unlikely got retrenchment.. you just have to stay focus and endure thru the 4 years..
And if your performance is good during your stay with them, they might even offer you a graduate post after you finish your degree...
However if you still want to leave the place anyway... chances is that it might be easier to get a job with your stat board experience than with army experience....
This is just sharing from my personal experience... i almost signed on with the air-force after ORD but later decided not to..
Already graduated and got em-placed into a graduate job.... But still... what had worked for me might not work for you... You might decide that Army suit you more... So i guess you have to decide what you want yah.. Good luck...