My family split a day between AK and DHS earlier this week -- your plan is definitely doable, especially if your park days are a little less crowded than ours were. DH, DD7 and I started the morning at AK, rode EE three times back to back at RD, then met Grandma and Grandpa at the Safari (5 minute wait, even after we stopped for coffee and donuts on the way). Met Pocahontas, rode Kali, then had lunch at Tusker House. Did not use any FP+ at AK. Hopped on a direct bus to HS at about 1:30 pm. Turns out we did not use our FP+ there, either. We watched the Frozen Sing-Along, Indiana Jones, MuppetVision, rode Star Tours, all standby. We had FP+ for TSMM, but a 45 minute wait for FP dissuaded us from using it. Also had one for ToT, but DD7 chickened out. When we approached Star Tours, the standby line was shorter than the FP+ line. We headed back to our resort at 5:30 pm, met Grandma, Grandpa and our cousins for dinner, then let the kids have an evening swim. Have fun planning your day!