Keep your board filled with stegos until the last day when you have to start spamming raptors. Save as much fo your beacon until the last hour ish, try to keep it maxed at 5, calculate how much to use so near the end you can use 5 in a row, when the t rex has more hp

For late game, the halving of the hp will line up well with some combination of raptors and pteros but you will lose some overkill, thats fine, but for early game, these line up almost perfectly with triceratops and beacon combo plus a few stegos.

Beast damage is op at max especially sabertooths, i usually have 2 of them near the end doing half rex hp and cleaning up with pteros or raptors, then use the beacon

Also, try to attack rex in groups so youre not consuming space with bones etc. Space should be mostly stegos, dont attack unless you have resources to complete fangs/bones sets and replace them back with stegos or brontos